Topped with peanut butter frosting.
Preheat oven to 350. Grease and flour and Bundt cake pan; set aside.
Do NOT follow the cake mix package directions.
In a large bowl, beat together the cake mix, sour cream and eggs until smooth.
Pour HALF of this batter into the prepared Bundt cake pan.
Evenly spread out the 12 halved pieces of mini peanut butter cups over the batter.
Evenly top with remaining batter.
Bake at 350 for about 50-60 minutes (or 325 for dark pans) or until toothpick tests done.
Allow to cool for 10 minutes and turn upside down to release the cake. Cool completely.
Peanut Butter Frosting
Cream butter and peanut butter together.
Add half the powdered sugar and blend.
Blend in milk and vanilla.
Add remaining powdered sugar.
Stir until smooth and well blended.
Use a knife to spread onto cooled cake, and then sprinkle with crushed peanuts.
Decorate with added chocolate pieces if you like.