Preheat the oven to 375 degrees Fahrenheit. In a small bowl, sift 2 cups of the flour with the baking powder. In a medium bowl, cream the butter and sugar until fluffy. Add the eggs, one at a time, then add the vanilla. Add the flour mixture to the creamed mixture, alternating with the milk. Mix until just combined. In a small bowl, add 1 tablespoon of flour to the frozen blueberries. Fold the blueberries into the batter. Line a 12 cup muffin tin and fill with batter. Sprinkle the crumble mixture on top of each muffin. Bake for 30 minutes or until a toothpick comes out clean.