In a large bowl, use an electric mixer to beat the butter and sugar until light and fluffy; blend in the egg. Add the flour and mix until well combined.
Spread the dough on the bottom and 1½ inches up the sides of a 9 inch springform pan. Bake for 5 to 10 minutes.
FILLING
In a large bowl, use an electric mixer to combine the cream cheese, sugar, zest and vanilla at medium speed until well blended. Add the eggs, one at a time, mixing well after each addition.
Pour the filling on top of the baked crust. Bake for 50 minutes. OPTIONAL: You can bake the cheesecake with a water bath, if you'd like (see tips below).
TOPPING
Stir together the topping ingredients in a medium bowl and spread evenly over the baked cheesecake; continue baking for 10 minutes. Remove from the oven and set on a cool stove.
Loosen the cake from the rim of the pan; cool before removing the rim of the pan completely. Chill for a few hours before serving.
Serve with fresh berries, if desired.
Notes
Here’s how to bake cheesecake in a water bath:
Wrap outside of pan in a double layer of foil, covering the underside and extending all the way to the top. Although a good crust keeps filling from leaking out, foil helps protect against water leaking in.
Set wrapped pan in a large roasting pan, and pour hot water into roasting pan, to a depth of 2 inches or about halfway up the sides of cheesecake pan.
Carefully transfer to a preheated oven and bake according to your recipe, until center jiggles when you bump the pan from the side. The outer 2 to 3 inches should not move, and the middle should wobble ever so slightly, like Jell-O.