For my raspberry muffins I used the same base recipe as my blueberry muffins, I just changed a few little details. They are delicious and perfect.
1 stick unsalted butter room temp
1 cup sugar
2 large eggs
1 tablespoon Vanilla
2 cups flour
1 1/2 teaspoon baking powder
1/2 teaspoon salt
1/2 cup milk
2 cups raspberries
12 cup muffin/cupcake pan I use cooking spray instead of butter and flour but whatever works for you is good.
In a separate bowl mix flour, baking powder, and salt stir together.
Cream butter and sugar until light and fluffy. Add eggs one at a time mix well, add vanilla. Add flour mixture, mix until combined then add milk until just mixed. Fold in raspberries by hand.
I used a large ice cream scoop to fill the muffin cups and bake for 30 min at 375 degrees.