Some good recipes.
Easy Four-layer Chocolate Cake
Source: Cake adapted from my Grandma's Chocolate Sheet Cake Recipe. Frosting adapted from the back of the C&H powdered sugar box.
Servings: Makes one big ol' cake.
Prep Time: 1 1/2 hoursCook Time: 30 minutes
For the Cake Baking -
Preheat oven to 350F. Melt the two sticks of butter in a saucepan over medium heat. Whisk in cocoa, salt & beer while bringing to a boil (still over medium heat). In your mixing bowl, whisk flour, baking soda, and sugar. With your mixer on stir, incorporate the hot mess in the saucepan into the dry goods. Once it's together, (about 2 minutes), add buttermilk, slightly beaten eggs, and vanilla and continue to stir for another 2 minutes. Grease the bottom of a half sheet pan and line it with a sheet of parchment, then grease and flour the pan with the parchment in place. Pour the cake batter into the pan, distribute evenly with a spatula, and bake for 25 minutes or until the toothpick test is passed. Cool the cake on a wire rack for 15 minutes, then loosen the edges with the reverse edge of a butter knife. Carefully invert the cake onto a wire rack (do NOT remove the parchment), then take a deep breath and then re-invert onto a second wire rack. Cool the cake completely, then bundle it up in plastic wrap and freeze until it's time to assemble.
For the Frosting -
Back to the stand mixer with the whisk attachment (and a clean bowl), dump in the butter, vanilla, milk, sour cream, and cocoa. Mix on medium speed until integrated, then slow to a stir and gradually add the powdered sugar. Once it's all in there, scrape the bowl, then crank the mixer back up to medium for about 3 minutes to finish. You'll know it's done when the frosting is smooth and lightens in color (don't over-mix).
To Decorate -
Get the cake out of the freezer and put it on a cutting board parchment-side down (you did leave the parchment on, right?). Using the biggest chef's knife you got, cut the cake into 4 equal rectangles, roughly 6" x 8" (there's no shame in getting out a ruler). Onto your cake delivery vessel (or plate) place the first cake layer parchment side UP. Carefully remove the parchment, and using an offset spatula spread on about 2/3 cup of frosting. Keep a tall vessel of warm water around in which to dip your spatula to ensure easier spreadage. Repeat the stacking / frosting process with layers two and three, but for the last layer frost with 3/4 cup of frosting on the top. Use what remains to even out the sides. Top with M&Ms and then add a little frou-frou to the base and edges with any remaining frosting.
For the Cake Baking -
You might be able to shave some prep time off this. I'm an extremely slow cake decorator.