COMBINE flour, brown sugar, cinnamon and butter in small bowl with fork until mixture resembles coarse crumbs. Stir in pecans.
PREHEAT oven to 375° F. Grease or paper-line 12 muffin cups.
COMBINE 1 cup morsels, milk and butter over hot (not boiling) water. Stir until morsels are melted and mixture is smooth.
COMBINE flour, sugar, baking powder, cinnamon, pecans and remaining morsels in large bowl.
COMBINE egg, vanilla extract and melted morsel mixture in small bowl; stir into flour mixture just until moistened. Spoon into prepared muffin cups, filling 2/3 full. Sprinkle with Topping.
BAKE for 20 to 25 minutes. Cool in pan for 5 minutes; remove to wire rack to cool completely.