Preheat your oven to 180C/350F. This is an essential step to ensure that your cake bakes evenly from the moment it goes in. An adequately heated oven will help achieve that lovely golden crust we all love.
Grease an 8 x 8-inch pan and set it aside. Greasing the pan with butter or cooking spray will help the cake release easily once it’s baked.
In a mixing bowl, combine almond flour, tapioca flour, light brown sugar, baking powder, and cinnamon. Use a whisk to ensure everything is evenly mixed, helping to create a uniform cake.
Add the eggs, melted butter, milk, and vanilla extract to the dry ingredients. Mix until everything is well combined and you have a smooth batter. The mixture should be thick yet pourable, showing a cohesive blend of flavors.
In a separate bowl, whisk together the crumb topping: oat flour, butter, light brown sugar, and cinnamon. This crumb topping will be sprinkled over the cake before baking, adding delicious texture and flavor.
Transfer the cake mixture into the greased pan, smoothing it out evenly with a spatula. This ensures each piece will have a beautiful shape once baked.
Sprinkle the crumb topping generously over the cake mixture. The more crumb topping, the better! This topping is what makes the cake special, giving it a delightful crunch.
Bake the coffee cake in the oven for 35 minutes. Keep an eye on it; it should turn golden on top, and a toothpick inserted in the center should come out clean.
Once baked, remove the cake from the oven and let it cool completely in the pan. This cooling period allows the flavors to deepen and the cake to set properly.
Before serving, drizzle with a simple glaze made from confectioners' sugar and a little water. This adds a sweet finish and makes the cake even more appealing.
