Cream together butter and sugars.
Add the egg and mix together.
Now add the baking soda, baking powder, salt, and vanilla and mix together.
Add one cup of flour and mix.
Sprinkle 1/2 cup of flour onto a clean surface and turn dough out onto it.
Mix by hand until the flour is incorporated. Add the remaining 1/4 cup of flour as needed. Dough should not be too sticky or too dry.
Add the broken Cadbury Mini Eggs and mix together.
Roll into a log and slice into 24 pieces.
Place dough on an un-greased cookie sheets and top with extra Cadbury Egg pieces if desired.
Bake at 375 degrees for 9 minutes.