1. Preheat the oven to 325 degrees. Spray a 10 inch springform pan with cooking spray and place on a baking sheet covered with foil.
2. In the bowl of a stand mixer, combine the flour, sugar, baking soda, baking powder and salt. Mix until combined, then add in the butter and mix until crumbly.
3. Add in the eggs, lemon extract, vanilla extract and milk. Mix until combined.
4. Pour the mixture into the prepared springform pan and spread to the edges. Tap on the counter to remove any air bubbles and settle the cake.
5. In the bowl of a stand mixer, beat the cream cheese and sugar until combined, then add in the egg, lemon zest and lemon extract. Mix until combined, then spread this mixture on top of the cake batter.
6. In a small bowl, whisk together the melted butter, flour, brown sugar, sugar and salt. Sprinkle over the top of the cream cheese filling mixture.
7. Bake for 40-45 minutes or until set in the center. Allow the cake to cool completely before releasing the sides of the springform pan, transferring to a plate and slicing and serving. Store leftover cake in the refrigerator.