Tender, bakery-style raspberry muffins crowned with a buttery cinnamon streusel. Bursting with juicy berries and a crunchy crumb top, they bake up beautifully in under 40 minutes.
Preheat oven to 375°F. Line a 12-cup muffin tin with paper liners or lightly grease.
Make the streusel: In a bowl, combine 0.75 cup flour, 0.5 cup brown sugar, 0.5 tsp cinnamon, and 0.125 tsp salt. Cut in 0.25 cup cold butter until pea-size clumps form. Refrigerate while you make the batter.
Whisk the dry batter ingredients: In a large bowl, whisk 2.0 cups flour, 2.0 tsp baking powder, 0.5 tsp baking soda, and 0.5 tsp salt.
Whisk the wet ingredients: In another bowl, whisk 1.0 cup milk, 0.5 cup oil, 2 large eggs, 1.5 tsp vanilla, 0.75 cup sugar, and 1.0 tsp lemon zest (if using).
Combine: Pour the wet mixture into the dry ingredients and stir gently until just combined with a few small streaks of flour remaining. Do not overmix.
Fold in raspberries gently until evenly distributed.
Divide batter among muffin cups, filling each about 0.75 full. Crumble streusel over the top of each muffin and lightly press to adhere. Sprinkle coarse sugar if using.
Bake 20 to 23 minutes, until tops are golden and a toothpick inserted in the center comes out clean or with a few moist crumbs.
Cool in pan for 5 minutes, then transfer muffins to a wire rack to cool. Serve warm or at room temperature.
Notes
For frozen raspberries, use straight from the freezer and fold in gently to minimize bleeding. Store leftovers in an airtight container at room temperature for up to 2 days or refrigerate up to 5 days. Muffins freeze well for up to 2 months.