In a medium-sized mixing bowl or the bowl of a stand mixer, mix butter and sugar.
Melt the chocolate in the microwave or in a double boiler.
Add chocolate to the butter/sugar mix and mix all together
Add in eggs and egg yolks one at a time mix with butter mix
Add in oil, vanilla, and sour cream mix in until all combined
Sift flour, salt, baking soda, and cocoa powder into a separate medium bowl.
Add dry ingredients to wet ingredients, mixing all together
Mix in whole milk
Blackberry Compote Directions
In a saucepan combine all ingredients and bring to a rolling boil.
Reduce heat and simmer until compote thickens.
Place to the side and let cool
Blackberry Frosting Directions
Add Butter, Blackberries to the mixer bowl set speed at medium
Now begin to add the powdered sugar one cup at a time and beat until well blended.
Increase the speed to med. speed until light and fluffy.
Place frosting in a pastry bag and pipe onto the top of the cupcakes.