Lemon Crumb Muffins Recipe

Preheat oven to 350 degrees F (175 degrees C). Grease or line 40 muffin cups with paper liners.

Mix 6 cups flour, 4 cups sugar, baking soda, and salt together in a large bowl. Whisk eggs, sour cream, melted butter, lemon zest, and lemon juice together in a separate bowl until smooth; pour egg mixture into flour mixture. Stir until just combined. Pour batter into the prepared muffin cups, filling them 3/4 full.

Mix 3/4 cup flour and 3/4 cup sugar together in a bowl; cut cold butter cubes into flour mixture until mixture resembles coarse crumbs. Sprinkle crumb mixture atop each muffin.

Bake in the preheated oven until a knife inserted in the center of a muffin comes out clean, 20 to 25 minutes. Cool for 5 minutes in the pans before removing to wire racks to cool completely.