Rhubarb muffins with crumble topping

On the weekend we went to the Market, and we got some rhubarb. I got so excited for this, because I love baking stuff with rhubarb. I had a lull in my day on Monday, so I decided to make the rhubarb muffins I had been wanting to make. They were so good! I brought one for El when I met her for lunch today, in exchange for her strawberry rhubarb jam. I found my recipe on Foodland Ontario's website, and adapted it slightly. I think they turned out really well.
Now it's pouring rain outside, and I would love to be able to cook something else.... Pizza night??? Pizza and a movie on this rainy night sounds perfect.

1 cup all-purpose flour
3/4 cup whole wheat flour
1 cup granola
3/4 cup granulated sugar
2 tsp baking powder
2 tsp cinnamon
1/2 tsp salt
1/4 tsp nutmeg
2 eggs
3/4 cup 2% milk
1/3 cup canola oil
1 tsp vanilla
2 cup chopped rhubarb

1/4 cup oatmeal
1/4 cup brown sugar
2 tbsp margarine

1. In a medium bowl, combine flours, granola, sugar, baking powder, cinnamon, salt, and nutmeg.
2. In a large bowl, whisk together eggs, milk, canola oil, and vanilla.
3. Add dry ingredients to the wet ingredients, and combine just until combined. Stir in the rhubarb. Put into muffin tins.
4. In a small bowl, combine the oatmeal, brown sugar, and margarine until well combined, and sprinkle on top of the muffins.
5. Cook in an oven preheated to 375F for 15-18 minutes.