Lightly grease a muffin pan or line with paper cupcake liners. Heat oven to 375°.
Combine the 1 1/2 cups of flour, baking powder, and granulated sugar in a bowl; whisk to blend.
In another bowl, whisk together the egg, milk, and 1/2 cup of melted butter. Stir the milk and egg mixture into the dry ingredients, stirring just until moistened. Fold in the frozen raspberries.
Spoon the batter into the prepared muffin cups, filling about 2/3 full.
Combine the topping ingredients, stirring until blended and crumbly. Sprinkle over the muffins.
Bake muffins for about 20 to 25 minutes.
Makes about 12
Calories per serving: 222
Fat per serving: 11.7