Blueberry and Buttermilk Cake

Preheat the oven to 180 °C and prepare a baking dish (approximately 25 cm × 15 cm), lining it with baking paper.

In a small bowl, mix the ingredients for the crumble topping: 90 g of flour, 50 g of sugar, 5 g of cinnamon, and 50 g of cold butter cut into cubes. Quickly knead with your fingers until you get a sandy texture, then set the bowl aside.

Prepare the main batter: in a large bowl, mix the remaining 170 g of flour, 80 g of sugar, and baking powder. Add the egg, 150 ml of buttermilk, and 30 ml of rapeseed oil. Mix everything until smooth and pour the batter into the prepared dish.