Add almond flour, melted butter, vanilla and swerve.
Pat down into a 8 or 9-inch springform pan. Don't go up the sides. Not necessary.
Jab with fork all over. Bake for 10 to 15 minutes until done at 350 F (180C).
Stick in freezer for about 10 minutes.
Make Filling
Using a food processor, or a mixer, mix cream cheese until it is very smooth.
Add in sour cream, zest, swerve, Mix well.
Add vanilla. Add lemon extract (if using)
Add eggs by hand, until just mixed.
Pour into prepared pan.
Bake at 325 degrees for up to 45-55 minutes.or until the outside is set and the middle still jiggles a little. It will continue to cook.I t will get a golden brown. The internal temperature should be taken at 45 minutes to see where it's at. It's done at 150 degrees in center.
Turn oven off. Open oven door. Leave in for an hour. If you don't have time for that, it's okay. I didn't as I needed my oven. It might compact a little more, but that's okay. When that happens, I just stick inside microwave to cool.
Take cheesecake out. Allow it to cool for two hours. Remove from pan.
If you want sour cream on top, spread on after cooling and before refrigeration.
Refrigerate for at least six hours or overnight.
Serve as is, or with berries and fresh mint.
Notes
You can opt out of lime juice if you don't have it. To Make this cheesecake sky high, bake in an 8 inch cheesecake pan.