Heat oven to 400 degrees F. Lightly grease 18 muffin cups, or line them with
paper baking cups.
In a large bowl, combine egg, banana, oil and milk. Mix well. Add flour, brown
sugar and baking powder, stirring just until moistened. Set aside 1/4 cup of the
toffee bits; stir remaining toffee bits into the batter.
Fill prepared muffin cups 2/3 full with batter. Sprinkle with the reserved toffee
bits and bake for about 20 minutes, or until a wooden pick inserted in the center
of a muffin comes out clean.
Cool for 5 minutes in the pan on a wire rack. Remove
muffins and cool completely on the wire rack.