Preheat the oven to 180°C. Grease a 2 loaf pan and dust it with flour.
In a medium bowl, sift together the dry ingredients; flour, baking powder, baking soda, and salt. Set aside.
Using a stand mixer or electric mixer on medium speed, cream the butter, granulated sugar, and brown sugar until light and fluffy. Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.
Alternately add the dry ingredients and yoghurt to the creamed mixture, starting and ending with the dry ingredients. Mix until just combined, being careful not to overmix the batter.
Fold in the blueberries gently using a spatula, ensuring they are evenly distributed in the batter. Be careful not to break the blueberries.
Spoon the batter evenly into the prepared pan, filling each all the way to the top.
In a medium-sized bowl, whisk together the crumble ingredients: flour, brown sugar, melted butter, and cinnamon. Sprinkle the crumble mixture evenly over the cake batter.
Bake for 50-60 minutes, or until a toothpick inserted into the center of the cake comes out clean.
Allow the cakes to cool for 5 minutes in the loaf pan, then transfer them to a wire rack to continue cooling.
Notes
Serve the Blueberry Crumble Cake as a delightful and flavorful dessert. It pairs well with a dollop of whipped cream or a scoop of vanilla ice cream for an extra indulgence. The cake can be stored in an airtight container at room temperature for a few days or refrigerated for longer freshness. Enjoy this delicious treat any time of the day!