These Big Blueberry Muffins are as good, if not better, than the ones you'd get at a bakery. They are bursting with fresh berries, tender and moist, and topped with a crunchy streusel.
Make the streusel by combining all streusel ingredients in a bowl. Mix with a fork until mixture resembles coarse, lumpy sand. Keep chilled while you make muffins.
Set oven to 400F, with rack on lower middle position. Line standard muffin tins with 8 paper liners.
In a large bowl, add flour, sugar, salt, and baking powder, whisking to combine well.
In a 1-cup measuring cup, add the oil, egg, vanilla extract, lemon juice, and enough milk to reach 1-cup.
Gradually combine oil mixture with the flour mixture, folding batter together with a rubber spatula, just until batter remains a little lumpy and most of the dry ingredients are moistened - a few little dry streaks are perfect. Do not over-mix. Gently fold in the blueberries.
Fill lined muffin cups all the way to the top. Sprinkle with your prepared streusel topping. Place baking sheet underneath muffin tin, in case of any spillage.
Bake 20-25 min or just until a toothpick inserted in middle comes out almost clean, with a few tender crumbs attached.
Place muffin pan on a cooling rack and let cool completely in the pan before serving.
Notes
Recipe is for standard-sized muffin tin. Yields 8 muffins. Streusel can be made a day or two in advance and kept covered/chilled until ready to use.