Prep the pan and oven. Heat the oven to 375°F (190°C). Line a 12-cup muffin pan with paper liners or grease each cup.

Make the crumble. In a bowl, mix flour, brown sugar, salt, and cinnamon. Cut in the cold butter with a pastry cutter or your fingers until shaggy and clumpy. Refrigerate while you make the batter.

Whisk the dry ingredients. In a large bowl, whisk 2 cups flour with baking powder, baking soda, and salt.

Combine the wet ingredients. In a separate bowl, whisk the melted butter, sugar, eggs, vanilla, buttermilk, yogurt, and lemon zest until smooth.

Bring the batter together. Pour the wet mixture into the dry and stir gently until just combined. A few small lumps are fine. Don’t overmix.

Toss the berries. In a small bowl, toss the blueberries with 1 tablespoon flour. This helps keep them from sinking. Fold them into the batter with a light hand.

Fill the cups. Divide the batter evenly among the muffin cups, filling each about 3/4 full.

Add the crumble. Generously top each muffin with a handful of crumble. If you like extra crunch, sprinkle a little coarse sugar over the crumble.

Bake. Bake for 18–22 minutes, or until the tops are golden and a toothpick inserted in the center comes out clean or with a few moist crumbs.

Cool and enjoy. Let the muffins cool in the pan for 5 minutes, then transfer to a wire rack. They’re fantastic warm, when the crumble is most aromatic and the berries are jammy.