1Cream together the butter and sugars with an electric or stand mixer. Add the vanilla extract and egg yolk, and mix until combined. In a separate bowl, mix together the flour and salt. Add the dry ingredients to the wet and mix on low speed just until well incorporated. Using a wood spoon, stir in the mini chocolate chips. Chill dough for at least 30 minutes or up to two days in the fridge.
2Preheat the oven to 350 degree Fahrenheit and line cookie sheets with parchment paper. Roll out dough on a floured surface. Using the alphabet cookie cutters, cut out cookies and arrange on sheets at least 1/2 inch apart. Bake for 10-12 minutes.
1Preheat oven to 350°F. Butter and line three 8-inch rounds with parchment paper or a silicone baking mat.
2Combine the butter and sugars in the bowl of a stand mixer fitted with the paddle attachment and cream together on medium-high for 2 to 3 minutes. Scrape down the sides of the bowl, add the eggs, and mix on medium-high again for 2 to 3 minutes. Scrape down the sides of the bowl once more.
3On low speed, stream in the buttermilk, oil, and vanilla. Increase the mixer speed to medium-high and paddle for 4 to 6 minutes, until the mixture is practically white, twice the size of your original fluffy butter-and-sugar mixture, and completely homogeneous. Don’t rush the process. You’re basically forcing too much liquid into an already fatty mixture that doesn’t want to make room for the liquid. Stop the mixer and scrape down the sides of the bowl.
4On very low speed, add the cake flour, baking powder, and salt. Mix for 45 to 60 seconds, just until your batter comes together and any remnants of dry ingredients have been incorporated. Scrape down the sides of the bowl. If you see any lumps of cake flour in there while you’re scraping, mix for another 45 seconds.
5Spread the cake batter in an even layer in the pan. Give the bottom of your pan a tap on the countertop to even out the layer. Sprinkle the chocolate chips evenly over the cake batter.
6Bake for 30 to 35 minutes or until puffed and doubled in size and the center is set. When gently poked with your finger, the cake should bounce back slightly.
7Remove from oven and cool on a wire rack. Stored in the fridge or freezer, wrapped in plastic wrap, for up to 5 days.
1Combine cocoa and boiling water, stirring until cocoa has dissolved. With an electric mixer on medium-high speed, beat butter, confectioners' sugar, and salt until pale and fluffy. Reduce speed to low. Add melted and cooled chocolate, beating until combined and scraping down sides of bowl as needed. Beat in cocoa mixture.
1Take a layer of cake, frost it, sprinkle on broken up cookies and repeat until the top layer. Ice the last layer, top it with cookies and then insert "NERD" cookie toppers.