Preheat oven to 350°F

Spray 3 8-inch round baking pans with pam, line bottoms with parchment paper, grease again and set aside.

In small bowl combine cocoa and boiling water with a whisk until smooth. Cool.

In medium bowl stir together flour, baking soda and salt.

In a mixer, beat butter and sugar until fluffy.

Add eggs, one at a time and vanilla.

Slowly add the cocoa mix.

Add ⅓ of the flour mix, then the milk. Then ⅓ of flour and the sour cream. Then, add the past of the flour.

Mix well and divide into the pans.

Bake 28-30 mins until the toothpick comes out clean.

Cool and pop out of pans. Remove parchment . (cool and at this point you can freeze)

Beat all except the milk.

Once incorporated add the milk slowly and beat fluffy.

Combine butter, milk, corn syrup, and vanilla extract in small saucepan and heat over medium heat until butter is melted.

On low, add chocolate whisking to melt.

Remove heat and add sugar whisking smooth.

Let sit 5 mins.

Lay one cake layer on cake stand, frost. Top with next layer, frost and top with final cake.

Do a crumb coat. Chill and frost cake. Let set.

Pour over cake letting it drip down sides.

Let set in fridge.

Pipe on peanut butter rosettes and add pb cups, if desired.