Step 1

Heat oven to 325 degrees F. Grease bottom and sides of 8 1/2-by-4 1/2-inch loaf pan with butter or spray with cooking spray.

Step 2

In medium bowl, whisk flour, baking powder and salt. In separate large bowl, beat butter and sugar 1 to 2 minutes until light and fluffy. Beat in eggs, one at a time, until combined. Add lemon zest. Beat in dry ingredients alternately with milk, beginning and ending with flour mixture. Fold in blueberries. Pour batter into prepared loaf pan.

Step 3

To make crunch topping: In small bowl, combine sugars and flour. Using fingers or pastry blender, mix in butter until mixture resembles coarse meal. Sprinkle mixture over top of batter in loaf pan.

Step 4

Bake loaf 1 hour 15 minutes until toothpick inserted in center comes out clean. Transfer to cooling rack to cool completely. Run knife along edges of pan before removing loaf.