Preheat the oven to 350°F (175°C). Grease and flour a 9-inch round cake pan.

In a mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.

Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

In another bowl, whisk together the flour, baking powder, baking soda, and salt.

Gradually add the dry ingredients to the wet mixture, alternating with buttermilk. Mix until just combined.

Fold in the sliced strawberries and lemon zest.

Pour the batter into the prepared cake pan.

In a small bowl, mix together the brown sugar, flour, and cinnamon. Drizzle the melted butter over the mixture and stir until crumbly.

Sprinkle the topping evenly over the cake batter.

Bake in the preheated oven for 35-40 minutes, or until a toothpick inserted into the center comes out clean.

Allow to cool in the pan for 10 minutes before transferring to a wire rack to cool completely.