Preheat the oven to 325°F and grease and flour three 6 inch cake pans or two 8 inch cake pans. Set aside.
In a large mixing bowl combine softened butter and oil together until combined.
Add in sugar to the oil and butter, mix on high until pale yellow and fluffy.
Add the eggs mix to combine. Add the vanilla extract. Beat the mixture on high incorporate as much air as possible.
In separate bowl combine cake flour, salt, and baking powder. Alternate mixing in the dry ingredients and the milk in 2 batches, starting with the buttermilk and ending with the dry ingredients. It’s okay if the batter still has a few lumps in it–you don’t want to over mix it.
Split the batter evenly into the prepared pans and bake for 30 minutes or until the cake is a lightly golden brown. This will depend on your oven. Take out of the oven and transfer to a cooling rack.
Raspberry Filling
Add all filling ingredients to a sauce pan and cook over medium heat. Stirring frequently until reduced and thick.
Remove from stove and allow to cool.
Vanilla Buttercream
Place the softened butter and powdered sugar in a stand mixer fitted with a whisk attachment. Beat the butter and sugar together until combined. The mixture will be thick.
Switch to the beater attachment and add heavy cream and vanilla extract. Beat for 5 full minutes until light and fluffy.
Notes
TIP: Cake layers are easiest to decorate when cool. I prefer to wrap in plastic wrap and freeze for an hour prior to decorating.