Place the mixer on low speed and slowly incorporate the powdered sugar until all of it is incorporated.
8 cups (904g) powdered sugar
Pour the milk and vanilla slowly into the buttercream and allow it to mix until light and fluffy, about two minutes.
1/4 cup (59g) milk, 2 tsp vanilla extract
Cake Assembly:
Trim off the domed top of your cakes so they are level.
Place one cake layer on a plate or your cardboard circle. Spread a layer of chocolate buttercream on top of the cake about a quarter-inch thick. Spread half of the raspberry preserves on top of the buttercream. Repeat this with the next layer finishing up with a cake layer at the top.
1 1/4 cups raspberry preserves
Spread a thin layer of buttercream around the whole cake and place them in the fridge for 15 minutes. This is a crumb coat and will help hold the crumbs in while frosting the outside of the cake.
Add a thicker layer of buttercream around the cake and smooth out the edges.
Pipe swirls of buttercream onto your cake using a pastry bag fitted with a star piping tip.
Add raspberries to each buttercream swirl.
fresh raspberries
Notes
Use good quality cocoa powder because this will affect the flavor the most.
Don't use cold ingredients in the batter. Using room temperature ingredients helps the cake rise and mix into the batter easier.
If your buttercream seems stiff, try mixing it for an extra minute or two to help incorporate air to make it fluffy.
Don't skip the chill time for the cake or your layers of cake are sure to slide around.
Use a lazy susan if you don't have a cake turntable.
How to store: This cake is best enjoyed the day it's made, but it will keep for up to a week in an airtight container in the refrigerator. Let it sit on the counter for a few minutes, then serve.
How to freeze: You can freeze Chocolate Raspberry Cake for up to three months. Wrap it tightly in plastic wrap, then place it in a freezer-safe container or bag. Thaw the cake overnight in the refrigerator before serving.