Preheat oven to 320°. Spray a 9" spring form pan. Cut parchment paper to line the bottom and the sides. Press the parchment paper against the bottom and sides using the spray to make it stick.
Melt the butter and stir into the graham crumbs. Press the graham crumb mixture evenly across the bottom and up the sides of the pan.
Cut the cream cheese into cubes. Beat on medium high about 4 minutes. Add the flour and beat just until incorporated, about 5 seconds. (Do not over beat. The aeration is what causes the cheesecake to crack while baking.)
Add the vanilla, sour cream, sugar and lemon zest. Beat until just mixed (about 10 seconds).
Add the eggs one at a time and beat about 5 seconds after each addition.
Pour the cheese mixture into the crust base.
Bake about 55 minutes. The center make slightly jiggle when gently shaken but be starting to turn golden brown.
Crack the oven door and allow the cheesecake to cool about 30 minutes. Transfer to refrigerate for 4 hours.
For the topping, hull the strawberries. Halve half of them and dice the rest.
Bring the chopped strawberries, vanilla, sugar and lemon juice to a simmer in a large saucepan. Simmer 10 minutes.
Mix the cornstarch and water, add to the saucepan and stir thoroughly. Cook a bit till mixture starts to thicken. Add the halved strawberries and cook 1 minute more.
The sauce should be syrupy. If it is too thick add a bit of water so it will be thick but able to drip down the sides of the cheesecake when cut.
Remove from stove and allow to cool. Topping will thicken more as it cools.
When cool pour the topping over the top of the cooled cheesecake. Do not let it spill over the top edge of the cheesecake. Turn the halved strawberries cut side down in a circular arrangement on top of cheesecake. (You will have additional sauce that you will refrigerate and pass with the cut cheesecake.) Refrigerate with topping 2 hours.
To serve, remove sides of springform pan. Slide the cheescake off the base of the pan onto a serving platter. Gently run an offset spatula between the crust and the parchment to loosen the parchment. Gently pull the parchment paper out from under the cheesecake.
Cut and serve with additional strawberry sauce.