Preheat oven to 375. Prepare 12 muffin cups with cooking spray and flour; set aside. In a mixing bowl, combine flour, brown sugar, cocoa powder, baking soda, and salt. In another mixing bowl, combine margarine, 1/3 cup milk, and egg whites. Mix dry ingredients with wet ingredients just until moistened; set aside. In a smaller mixing bowl, combine cream cheese, peanut butter, honey, remaining milk, and vanilla extract. Place 2 tablespoons batter into prepared cups. Spoon rounded teaspoon of cream cheese mixture into center of each. Fill cups half full with remaining batter, 1 tablespoon each. Bake for 20 minutes. ----