Not overly sweet but delicious and fluffy chocolaty chocolate cake. 4 layers of goodness.
Place rack in center of oven and heat to 350 degrees F. Lightly butter 2 (9-inch) pans and dust sides with cocoa; tapping out excess. Set aside. In a large bowl, combine 3/4 C cocoa, sugar, flour, baking powder, baking soda and salt. Add butter, milk, eggs and vanilla. Using a hand-held electric mixer or a Kitchenaide on medium speed; beat for 2 minutes. Add boiling water and beat to combine (batter will be thin). Divide batter evenly between pans. Bake until cake center comes out clean, 30 to 30 minutes. Cool in pans for about 10 minutes. Run knife around edge of cakes to loosen them from the pan. Cool cakes or racks completely. Slice both layers and slap on the icing. (Make sure the cake has completely cooled).
In a medium saucepan, melt butter. Add cocoa and beat with a hand held electric mixer to combine. Let sit and cool down. Alternately add confectioners' sugar and milk while beating, add vanilla and beat until it becomes creamy. Build cake with frosting on every layer, then frost cake top and sides.