This blueberry coffee cake is made with a moist and soft cake filled with blueberries, and cinnamon filling, and topped with a buttery and crunchy crumble topping.
In a small mixing bowl, add the flour, brown sugar, and cinnamon. Mix with a spoon until well combined.
Add the softened butter and mix with your clean hands until wet sand-like mixture forms.
Make the crumble topping
Into a medium mixing bowl, add the flour, brown sugar, and cinnamon. Mix with a spoon until the mixture is well combined.
Add the melted butter and mix until well combined and place in the fridge while you make the cake.
Make the cake
Into a large mixing bowl, add the softened butter, lemon zest, sugar, vanilla extract, and kosher salt. Mix with an electric hand mixer until well combined.
Add the yogurt and eggs, and mix until the mixture is smooth.
Add ½ of the flour, baking soda, and baking powder, and mix until almost combined.
Add the buttermilk and the rest of the flour, and mix until almost combined.
Add the blueberries and mix until just combined. Don't overmix!
Pour ½ of the cake batter into a parchment paper lined 9 by 13 baking pan and spread it with a spatula. Top it with an even coat of cinnamon filling.
Top with the rest of the cake batter and carefully spread it with a spatula.
Top the cake with the streusel topping and press the streusel topping onto the cake batter so it sticks and does not fall off while baking.
Bake in a 180c (350f) preheated oven for about 40-45 minutes or until a toothpick inserted into the cake comes out clean, usually with a few crumbs.
Notes
Push the streusel topping onto the cake lightly so it would stick to the top of the cake while baking and not fall off.
Use room temperature ingredients. It is important that you use room-temperature ingredients like eggs and milk. This step ensures that your mixture mixes into a homogenous mixture and bakes perfectly. you don’t want to place cold batter into the oven.
Don’t overmix the batter, you don’t want to develop the gluten in the flour. This step ensures you have moist cake and not dense and dry cake.
Measure your flour correctly! When measuring your flour, avoid scooping it with a measuring cup. Instead, stir the flour with a spoon to create as many air pockets as possible, and spoon it into your measuring cup. Finally, level it with a back of a knife.
Add some of your favorite add-ins! Make this recipe your own and add your favorite cake add-ins: chocolate chips, chopped walnuts, chopped pecans, chocolate chunks, banana slices, chopped fruit, and more! Be creative!
Be patient! I know it's extremely tempting to eat this cake as it is pulled out of the oven, but let this cake cool for at least 1 hour so it will be more firm and won't crumble up.