Remove cream cheese, eggs, and sour cream from refrigerator 2 hours before baking. Preheat oven to 350°F (175°C). Grease springform pan, line with parchment paper, and wrap exterior with heavy-duty foil.
Combine graham cracker crumbs, sugar, and melted butter in a bowl. Press mixture firmly into bottom of prepared pan. Bake for 10 minutes and cool slightly.
Beat cream cheese on medium speed for 3-4 minutes until smooth. Add sugar and mix for 2 minutes. Add sour cream, vanilla, lemon juice, and zest. Mix in flour. Add eggs one at a time on low speed, mixing just until combined.
Pour filling into cooled crust and smooth top. Place springform pan in a roasting pan and add hot water to reach 1 inch up the sides. Bake at 350°F for 55-65 minutes until edges are set and center jiggles slightly.
While cheesecake bakes, stir together sour cream, sugar, and vanilla for topping. When cheesecake is done, spread topping over the surface and return to oven for 10 minutes.
Turn off oven and prop door open 1-2 inches. Leave cheesecake inside for 1 hour. Remove from water bath and cool completely on a wire rack for 1-2 hours.
Run a thin knife around the edge, cover loosely with plastic wrap, and refrigerate for at least 6 hours or overnight. Remove from pan, slice with a warm knife, and serve.