Preheat the oven to 350 degrees. Grease 8x8 pan and set aside
In a small saucepan, melt together all cinnamon swirl ingredients and set aside
In the bowl of a food processor, add all crumb topping ingredients, pulsing several times to a crumb consistency
To make the cake batter, whisk together all dry ingredients. In a blender, blend the melted butter, eggs and vanilla until slightly frothy. Add the dry ingredients and blend to a smooth batter. Scrape down the sides and blend again.
Pour the cake batter into prepared baking dish. Next, slowly drizzle the cinnamon swirl butter around the pan, using a toothpick swirl the butter into the cake batter. Finally, sprinkle on the crumb topping, evenly covering the top of the cake.
Bake in oven for 20-25 minutes, or until toothpick comes out clean. Allow cake to cool for 10 minutes before slicing. Enjoy