Preheat the oven to 350F and grease an 8x8" cake pan.
Mix all of the cake ingredients together, pour into the prepared pan. Bake at 350F for 30-40 minutes until a toothpick inserted in the middle comes out clean.
Turn up the oven to 375F.
Crumble the cooled cake into a 9x13" pan, you want small crumbles, bigger pieces prevent it from binding together and make the base crumbly.
Drizzle the melted butter over the cake crumbs, toss them around to coat and then press the cake crumbs down to form the base. Use a smaller pan to help compact the crumbs.
Bake at 375F for 15 minutes until brown and toasty.
Turn down the oven to 325F.
In a stand mixer with a paddle attachment cream together the cream cheese and sugar until smooth and fluffy. Scrape down the sides of the bowl and blend again.
While the mixer is on add one egg at a time until fully incorporated, scrape down the sides and blend again.
Add the remaining ingredients, sour cream, lemon juice, vanilla and salt. Beat for 1 minute.
Pour the cream cheese mixture on top of the cooked cake base pushing it to the corners. Lightly drop the pan a few times to help pop the air bubbles.
Bake at 325F for 35-45 minutes until the top is lightly browned, the edges are set and the center is still a little giggly. If the top is getting too dark, drape a piece of foil over the top to prevent it getting darker.
Let cool completely and then chill for a few hours before slicing into squares.