Preheat the oven to 375 degrees. Prepare a muffin tin with paper liners, or spray with nonstick spray.
In a large bowl combine all the muffin ingredients and stir until the mixture forms a batter. Spoon the batter into each well of the muffin tin, filling about 2/3 full.
In another bowl, mix the streusel ingredients together until coarse crumbs form. Spoon about 2 tablespoons of the streusel topping over the muffin batter.
Bake for 15-20 minutes, or until a toothpick inserted into the center of a muffin comes out clean. Cool on a wire rack for 5 minutes and then remove from muffin pan.