Preheat the oven to 350 degrees F (175 degrees C). Coat an 8-inch springform or cake pan with cooking spray and line the bottom with parchment paper; set aside.
Stir flour and sugars together in a small bowl with a fork. Add melted butter and mix until crumbly, leaving some large crumbs. Set topping aside while you make the cake.
Combine butter, sugar, and lemon zest in a large bowl and cream with an electric mixer until light and fluffy, about 3 minutes. Add eggs, lemon juice, baking powder, vanilla, salt, and cinnamon. Beat until well combined, about 3 minutes. Add in flour gradually on low speed, mixing until combined. Add sour cream and milk and mix batter until smooth, about 4 minutes.
Fold white chocolate chips into the batter. Pour into the prepared pan and sprinkle with the topping.
Bake in the preheated oven until light golden brown and a toothpick inserted in the center comes out clean, about 40 minutes. Cool on a wire rack for about 30 minutes before removing from the pan and serving.