Preheat oven to 350 degrees Fahrenheit. Grease muffin tins.

For the batter: In a bowl, mix dry ingredients well with a whisk. Add wet ingredients and mix until the batter is smooth. Pour into muffin tins and place in the oven for 10 minutes.

Meanwhile, prepare the crumb ingredients: In a medium bowl, combine all the ingredients and mix until crumbly.

After muffins are in the oven for 10 minutes, take them out and place crumbs on top of the half-baked muffins. Place back in the oven for another 10 minutes or until done.