Banana muffins with Streusal Topping

Ingredients for the muffins
* 2 cups of DIY Bisquick mix (or boxed Bisquick mix if you use that)
* 1/3 cup sugar
* 1 cup mashed ripe bananas (about 3)
* 2/3 cup milk
* 1 egg, slightly beaten
* 1/2 tsp cinnamon

Ingredients for the topping
* 1/4 cup flour
* 1/4 cup packed brown sugar
* 2 tbsp cold butter
* 1/4 tsp cinnamon

Directions
1.  Preheat the oven to 400 F.
2. Mix all the muffin ingredients together.  Split evenly among greased muffin cups.
3. Mix the flour, brown sugar and cinnamon.  Using a pastry cutter cut in the butter.  Sprinkle the topping over the batter.
4. Bake the muffins for 17 minutes, or until a toothpick comes out clean.  Cool 10 minutes in the pans, then turn onto a wire rack.  Serve warm or room temperature.

Notes
We used skim milk, since we had that on hand, as well as the DIY Bisquick mix that we make.  These came out great, and our batter made 16.  Easy and delicious!  I also only used a little over 1 tbsp butter since that is what was in my fridge, and it worked out fine.