Cake: Heat oven to 350 degrees F. Grease and flour a 10-inch tube pan.
In a large mixing bowl, combine butter, peanut butter, sugar and vanilla
extract; beat until light and fluffy.
Add eggs, one at a time, beating well after each addition.
In another bowl, combine flour, baking powder and salt; stir into butter mixture
alternately with milk.
Pour into greased and floured pan.
Bake at 350 degrees F until a wooden pick inserted in center comes out clean,
about 1 hour and 15 minutes.
Cool in pan for 15 minutes on wire rack.
Remove from pan. Cool completely on wire rack.
Frost cake with Buttercream Peanut Butter Frosting.
Buttercream Peanut Butter Frosting: Place the butter and peanut butter in a bowl and beat until combined.
Slowly add the sugar while the mixer is running. As the mix starts to thicken begin adding
the mile one tablespoon at a time. Continue to add the milk until the frosting
becomes smooth and spreadable.
Add vanilla extract. Beat for three minutes or until the
frosting is light and fluffy.
When cupcakes have been frosted, sprinkle with chocolate shavings.