Raspberry streusel muffins

1 3/4 cups flour
1/2 cup sugar
2 teaspoons baking powder
1/2 cup and 2 tablespoons melted butter, measured separately
1/2 cup milk
1 beaten egg
1 cup fresh or frozen raspberries
1/4 cup nuts
1/4 cup brown sugar
2 tablespoons butter

Mix 1 1/2 cups flour, sugar, baking powder, 1/2 cup melted butter, milk and egg together. Add raspberries. If raspberries are frozen, drain well. Do not overmix. Put into muffin cups. In a separate bowl, combine nuts, brown sugar, 1/4 cup flour and 2 tablespoons melted butter to create the crumble topping. Put topping onto each muffin before baking. Bake muffins at 370 degrees for 20-25 minutes.