Preheat oven to 350F and grease a 9" cake or springform pan.
Streusel topping – In a small bowl, mix the flour, sugar, and lemon zest. Add the melted butter and combine with a fork until all is moistened and some large clumps remain. Set aside in the fridge to chill.
1 cup (125g) all-purpose flour, ⅓ cup (65g) granulated sugar, zest of 1 lemon, 4 Tbsp (57g) unsalted butter
Cake batter - In a medium bowl, combine the flour, baking powder, and salt. Set aside.
1 & ½ cups (190g) all-purpose flour, 2 tsp baking powder, ¼ tsp salt
In a large bowl, whisk together the melted butter and sugar. Add the buttermilk, egg, vanilla extract, and lemon zest. Whisk again to combine.
½ cup (114g) unsalted butter, ¾ cup (150g) granulated sugar, ½ cup buttermilk, 1 large egg, 1 tsp vanilla extract, zest of 1 lemon
Add the flour mixture to the wet ingredients and stir until just combined. Spread the batter evenly into the prepared pan.
Toss the strawberries with the flour to coat and layer on top of the cake batter. Sprinkle the crumb topping over the strawberries.
2 cups strawberries, 2 Tbsp all-purpose flour
Bake 45-50 minutes or until a toothpick inserted into the center comes out clean. Let cool completely before glazing.
In a small bowl, whisk together the powdered sugar and a teaspoon of lemon juice at a time until you reach a thick but pourable consistency. Drizzle over cake before serving.
½ cup powdered sugar, 1-2 tsp lemon juice
Notes
Leftovers can be covered or placed in an airtight container and stored at room temperature for up to 2 days or in the refrigerator for up to 4 days (especially if your kitchen is warm or humid). For the best texture, bring to room temperature before enjoying.