In a medium bowl mix together the flour, baking powder, baking soda, and salt and set aside
In a large bowl use an electric mixer to beat the 1/3 cup butter and 1 cup sugar until light and fluffy.
Beat in the zest from 1 lemon and the egg
Mix in 1/3 cup of the flour mixture to the butter and sugar mixture, followed by the lemon juice.
Mix in another 1/3 of the flour mixture, followed by the buttermilk. Mix in the remaining flour mixture just until the dry ingredients are mixed in.
Pour the batter into the prepared springform pan. Place the sliced strawberries over top of the batter.
Sprinkle the crumble topping over the strawberries. Place in the preheated oven and bake for 45 to 50 minutes or until a wooden pick comes out clean.
Remove from the oven and place on a cooling rack to cool.
In a small bowl add the 1/2 cup powdered sugar and enough lemon juice to make an icing. Drizzle over a slightly cooled coffee cake.