Preheat oven to 400 degrees.
Begin by mixing the streusel ingredients: in a small bowl, mix flour, brown sugar, and cinnamon.
Cut butter into small chunks and mix it in to dry ingredients using pastry cutter or hands until mixture resembles sand. Set aside.
In another bowl, combine all dry ingredients for muffins.
Make a well in the center and pour in beaten egg, milk, oil, and extract.
Stir gently until just combined. Do not over mix.
Line 12 muffin cups with paper liners; spray liners with nonstick spray.
Divide muffin batter among cups, the evenly distribute streusel topping on top of batter.
Bake for about 16 minutes until tops of muffins spring back when touched.