So it turns out this cake has more ingredients than any cake I have ever made! And when I started to write the cake description in the blog title, I realized that there are 18 words and two ampersands in the name. Yep. Okay, ready? The Autumn Delight cake is a 4-Layer Sweet Potato & Ginger Layer Cake with Toasted Marshmallow Filling, Candied Pecans and Brown Sugar & Cinnamon Buttercream. When I tried to edit that, I realized that each one of those ingredients are key, and I couldn't bare the thought of taking any words away. Okay, you're right, I'm just being silly, but most importantly I am really excited about this cake. In my heart, I am drawn to all thing pastel and sprinkly, but there is a big part of me that just loves autumny, spiced flavours. At this time of year, my sister-in-law, Mary, makes that gorgeous southern sweet potato casserole dish that you have likely heard of or tried, that marries sweet potatoes, brown sugar, marshmallows, vanilla and pecans, and I thought it would be a nice treat to create a cake version of that dish. So on with the apron and into the kitchen I went . . .What I love about this recipe is how moist, creamy, and unexpected some of the elements are. I made a sweet potato layer spice cake and added a generous quantity of crystallized ginger for texture and taste to the cake layers themselves, and then filled the cake with whipped toasted marshmallow filling that I sprinkled with candied pecans for crunch (you even get those little buttery brown sugary bits that fall off the pecans every now and then). Since the filling was quite sweet, I decided to frost it with a Brown Sugar & Cinnamon Swiss Meringue Buttercream that is fluffy, satiny and perfectly brown sugary and not-too sweet, in true Swiss Meringue Buttercream fashion. The neat part about making Brown Sugar Buttercream is that you essentially just switch the white sugar for brown sugar, and voila! The taste is really quite different and it was the perfect addition to this concoction--particulary when topped with a generous handful of the candied pecans and crystallized ginger.So think about it this way: Every bite is crunchy, then brown sugar creamy, then dense, moist & spicy, then sweet and crispy, oh, and then crunchy, and then dense, moist & spicy, and then sweet and crispy, and oh, yet again crunchy, then dense, moist & spicy, then, alas, sweet and crispy, and then dense, moist & spicy. Help me, Rhonda.If the sweet potato thing is throwing you off your dessert-loving game, well, don't fear. It's much like carrot cake or pumpkin cake, and the texture is like no other--it's dense yet light all at once. You have my word. I wasn't sure either, but now I am pretty certain.I once wrote that the Zingy Orange Ginger Carrot Cake with White Chocolate Icing is my ultimate-tasting cake, and I have always stood by that statement because I meant it. Well, this cake comes a close second or possibly ties for first. Or possibly the unthinkable: it could be even better.If you make this cake, just know that it does take some time, but I felt it was completely worth it, and I think it would make an incredible addition to any Thanksgiving event or any autumn day. Autumn Delight CakeSweet Potato & Ginger Layer Cake with Toasted Marshmallow Filling, Candied Pecans and Brown Sugar & Cinnamon ButtercreamFor the Cake Layers:3 large sweet potatoes (about 900 g)2 cups 400 g sugar4 large eggs (at room temperature)1-1/4 cups 315 ml sunflower oil (or vegetable, safflower, canola oil)2 cups 230 g cake flour1 tablespoon 7 g ground cinnamon2 teaspoons 8 g baking powder1 teaspoon 7 g salt1 teaspoon 3 g ground nutmeg1/2 teaspoon 1.5 g ground ginger2 tablespoons 30 ml brandy or dark rum2 teaspoons 10 ml pure vanilla extract3/4 cup 120 g crystallized ginger, choppedFor the Filling:16 large white marshmallows1 cup 125 g icing sugar (confectioners' or powdered), sifted1 cup butter (227 g(2 sticks), at room temperature)1/2 teaspoon 2.5 mL pure vanilla extract1 jar (213 g marshmallow cream (such as Marshmallow Fluff))For the Buttercream:5 large egg whites (150 g))1-1/4 cups 250 g light brown sugar1-1/2 cups 3 sticks(340 g) unsalted butter, softened and cut into cubes2 teaspoons 10 ml pure vanilla extractpinch of salta few pinches of cinnamon (to taste)For the Candied Pecans:2 tablespoons 28 g unsalted butter2 tablespoons 24 g brown sugar1 cup 100 g pecan piecesFor the Cake Layers:Preheat oven to 350°F. Grease two 8-inch round cake pans, dust with flour, tap out excess and set aside.Place the sweet potatoes on a microwave-safe plate and pierce them with a fork. Microwave until they are tender (about 7-8 minutes each side). Carefully remove the skin when cool enough to touch, and mash the flesh into a coarse puree.In the bowl of an electric mixer fitted with the paddle attachment, beat the sugar and eggs together on medium-high speed (I use #6 on KitchenAid) until light and fluffy, about 5 minutes. Add the oil and beat on medium until combined. Add the cooled sweet potato puree and mix until combined.Sift dry ingredients together (cake flour, cinnamon, baking powder, salt, nutmeg and ground ginger) and then add to sweet potato mixture.Mix in brandy/dark rum (I used dark rum) and vanilla. Gently stir in crystallized ginger.Evenly distribute batter into the prepared pans (weigh them if possible with digital kitchen scale), smooth with a small offset palette knife and place in the center of the middle rack of the oven, about 2 inches apart. Bake until a knife or skewer inserted into the center comes out clean, about 40 minutes.Let pans cool on a wire rack 10 minutes. Invert cakes onto rack and cool them completely.For the Filling:Place marshmallows on cookie sheet lined with parchment paper and sprayed with nonstick cooking spray. Place on lower rack of oven, and broil marshmallows until nice and brown on top, between 30-60 seconds. Remove pan from oven and gently turn the marshmallows over, and broil until they are golden brown. (Be sure to keep an eye on them--they burn very quickly.)In an electric mixer fitted with paddle attachment, combine butter and icing sugar on low until blended, about 1 minute. Add vanilla and mix on med-high for about 3 minutes.Add marshmallow cream and toasted marshmallows, and mix on lowest setting for about 1 minute.For the Buttercream:Wipe the bowl of an electric mixer with paper towel and lemon juice, to remove any trace of grease. Add egg whites and sugar, and simmer over a pot of water (not boiling), whisking constantly but gently, until temperature reaches 160°F, or if you don't have a candy thermometer, until the sugar has completely dissolved and the egg whites are hot.With whisk attachment of mixer, begin to whip until the meringue is thick, glossy, and the bottom of the bowl feels neutral to the touch (this can take up to 10 minutes or so). *Don't begin adding butter until the bottom of the bowl feels neutral, and not warm.Switch over to paddle attachment and, with mixer on low speed, add butter cubes, one at a time, until incorporated, and mix until it has reached a silky smooth texture (if curdles, keep mixing and it will come back to smooth). *If mixture is too runny, refrigerate for about 15 minutes and continue mixing with paddle attachment until it comes together. Add vanilla and salt, continuing to beat on low speed until well combined. Add cinnamon to taste and blend.For the Candied Pecans:Melt the butter in a small pan. Mix in brown sugar, and add the pecans. Toss to coat.Cook on medium low heat for about 15 minutes, stirring occasionally. Be sure to watch carefully so they don’t burn.Turn out onto parchment paper or aluminum foil and let cool for 5 minutes; break apart into smaller pieces if using halves.Assembly of the Autumn Delight CakeSlice both cake layers in half horizontally, so you have 4 cake layers.Place the first layer on a plate, pedestal or cake board cut side up (so bottom of the cake layer is touching plate), and spread ~3/4 cup of Toasted Marshmallow Filling with a small offset palette knife, leaving 1" or so around the edge. Sprinkle with a handful of candied pecans pieces.Repeat previous step until you get to the final cake layer. Place last layer face down and chill cake for 30-40 minutes.Frost cake with Brown Sugar Buttercream and top with a generous handful of candied pecans and crystallized ginger.Finished cake can be kept at room temperature for up to 8 hours. Keep refrigerated if longer than 8 hours, but always serve at room temperature (Swiss Buttercream should never be served cold, as it goes back to a cold-butter texture).For a bit more sparkle, you could even sprinkle a little Gold Edible Glitter on top for some extra wow! * You can make buttercream ahead and keep in an airtight container in refrigerator for up to one week, leaving out at room temperature when needed, re-whipping in mixer for 5 minutes.**Can freeze buttercream for up to 6-8 weeks. To thaw, place on counter overnight, and rewhip for 5 minutes with paddle attachment in an electric mixer. If not satiny enough upon rewhip, take 1/3 of buttercream and microwave in a microwave-safe container for ~8 seconds, then add back to mixing bowl and remix with remaining buttercream. [cake layer recipe adapted from Martha Stewart] Good luck & enjoy!