In a medium bowl, combine all of the ingredients for the streusel; stir until crumbly. Set aside.
MAKE THE MUFFIN BATTER:
Preheat the oven to 375°F. and line a muffin tin with paper liners.
In a large bowl, whisk together the flour, sugar, baking powder, cinnamon and salt; set aside.
In a small bowl, combine the milk, butter and egg until well blended. Stir into flour mixture just until moistened. Fold in the strawberries and lemon zest.
Spoon the batter evenly into the prepared muffin cups. Sprinkle the lemon streusel evenly on top of each muffin.
Bake for 20 to 25 minutes or until toothpick inserted into the center comes out clean. Remove from the pan. Cool on a wire rack for 10 minutes.
ADD THE GLAZE:
Combine sugar and lemon juice in small bowl, stirring until smooth. Set aside.
Drizzle the glaze over the tops of the warm muffins. Serve warm, or cool completely.