Fran's Blueberry Muffin

2 cups flour
3 tsp. Baking Powder
½ cup sugar
¼ tsp. Salt
½ cup butter
2 eggs
1 cup milk
1 cup frozen blueberries

Mix flour, baking powder, sugar and salt. Cut in butter. Add eggs and milk. Mix well ( you may want to add 1 tsp vanilla). Stir in 1 cup frozen blueberries. Bake in muffin cups at 350° for 25 minutes.