Blueberry Crumble Cake

1. Preheat the oven to 350 F and prepare an 8x8 pan by buttering/greasing it and lining it with parchment paper.
2. To make the crumble: In a small bowl, stir together the flour, sugar, and cinnamon. Add in chunks of butter and rub together with your fingers until mixture looks like coarse crumbs. Set aside.
3. In another small bowl, combine the cinnamon and sugar to make the cinnamon-sugar mixture. Set aside.
4. In a medium bowl, combine and sift the flour, cinnamon, baking powder, and baking soda. Set aside.
5. In a large bowl, mix together the sugar and melted butter until combined (about 45 secs). Add the eggs and whisk for about another minute.
6. Add in the buttermilk and vanilla until combined.
7. Sift and fold in the dry ingredients until almost combined. Fold in the blueberries.
8. Pour about half of the batter into the prepared pan. Sprinkle the layer of the cinnamon sugar then pour the rest of the batter on top followed by the crumble.
9. Bake in the oven for 45-60 minutes, or until a toothpick comes out clean. Baking times will vary based on the oven you have, type of pan you used, etc so watch your cake carefully!
10. Let it cool down completely before adding an (optional) glaze and enjoying!