Combine graham cracker crumbs, sugar, ground almonds, and salt in a bowl. Drizzle melted butter and stir until evenly moistened. Press into the bottom and up the sides (as far as it'll go) of a lightly buttered 10-inch springform pan. Refrigerate for at least 1 hour to set.
Preheat oven to 325 degrees F.
In a large mixing bowl or the bowl of a stand mixer, combine cream cheese, 1 cup of sugar, and salt and beat until smooth. Add flour and egg yolks and mix thoroughly. Stir in sour cream, lemon juice, vanilla and nutmeg and beat until smooth.
In a separate bowl, beat egg whites with remaining 1/4 cup sugar until it forms stiff peaks. Fold thoroughly into cream cheese mixture; no need to be terribly gentle with it, but you do want the whites to be evenly incorporated. Pour into chilled crust.
Bake cheesecake for 1 hour 15 minutes or until top is puffed and lightly golden brown. There will be cracks, but that's what the sour cream topping is for. Without opening the oven door, turn the oven off, and let the cheesecake sit in the oven as it cools for 1 hour. Do not take the cheesecake immediately out of the hot oven or it will fall. After an hour, remove cheesecake and heat oven to 450 degrees.
While the cheesecake is cooling, make the sour cream topping by whisking the sour cream, sugar and vanilla together until smooth. Once the cheesecake has cooled for an hour, pour the sour cream topping over top. Using a rubber spatula or offset spatula, smooth out the surface.
Place back into the oven (remember the heat should have been increased to 450° F) and bake for about 10 minutes. Remove from the oven and place on a cooling rack to let cool to room temperature.
Refrigerate the cheesecake overnight to set. ***Don't put cheesecake in the fridge until it has cooled to room temperature.***.