Step 1

Make the streusel topping by mixing brown sugar, flour, cinnamon, and salt in a bowl. Rub in the cold butter until crumbly. Refrigerate.

Step 2

Preheat oven to 375°F and grease a 9-inch square pan.

Step 3

Whisk flour, baking powder, and salt in a medium bowl.

Step 4

In a separate bowl, beat butter and sugar until creamy.

Step 5

Add eggs one at a time, then beat in vanilla and lemon zest.

Step 6

Gradually mix in the flour mixture, alternating with milk.

Step 7

Fold in the blueberries gently with a spatula.

Step 8

Spread batter evenly in the pan and sprinkle streusel over the top.

Step 9

Bake for 40–45 minutes or until golden and a toothpick comes out clean.<

Step 10

id=”instruction-step-10″>Cool in pan for 20 minutes before serving.