Preheat oven to 375°F (190°C). Line a 12-cup muffin tin with paper liners or grease it well.
In a large bowl, whisk together the flour, granulated sugar, baking powder, and salt for the muffins.
In a separate medium bowl, whisk together the eggs, milk, melted butter, and vanilla extract.
Pour the wet ingredients into the dry ingredients and stir until just combined. Do not overmix.
Gently fold in the chopped strawberries.
To make the coffee cake topping, combine the flour, brown sugar, and cinnamon in a small bowl. Cut in the cold butter with a pastry blender or your fingertips until the mixture resembles coarse crumbs.
Divide the muffin batter evenly among the prepared muffin cups, filling each about two-thirds full.
Sprinkle the coffee cake topping generously over the batter in each muffin cup.
Bake for 20-25 minutes, or until a wooden skewer inserted into the center of a muffin comes out clean.
Let the muffins cool in the tin for a few minutes before transferring them to a wire rack to cool completely.
Notes
These muffins are best enjoyed fresh. You can store them in an airtight container at room temperature for up to 3 days.