For the cheesecake:
Heat the oven to 325°F and arrange a rack in the middle. Generously coat the bottom and sides of a 9-inch springform pan with butter.
Place the wafer crumbs and melted butter in a medium bowl and mix until thoroughly combined.
Pour the crumb mixture into the prepared pan and, using the bottom of a measuring cup, press evenly into the bottom and slightly up the sides.
Mix together the sugar and flour in a medium bowl and set aside. Place the cream cheese in the bowl of a stand mixer fitted with a paddle attachment and beat on medium speed until smooth, about 1 minute.
With the mixer running, slowly pour in the sugar-flour mixture and beat until incorporated. Stop the mixer occasionally to scrape down the sides of the bowl and the paddle as needed.
With the mixer on low, add the lemon zest and vanilla and then slowly pour in the cream; mix until just combined.
Add the egg yolk, then the whole eggs 1 at a time, allowing each egg to incorporate completely before adding the next. Stop the mixer occasionally to scrape down the sides of the bowl and the paddle as needed.
Pour the filling into the prepared crust and spread it into an even layer. Bake until just the edges of the cake are browned and the center is barely set, about 45 to 60 minutes.
Turn off the oven and let the cake cool in the oven for 1 hour. (It will bake a little more as it sits in the hot oven.)
Remove the cheesecake from the oven and place it on a cooling rack.
Place a baking sheet over the cheesecake and let it cool, carefully removing the baking sheet every 30 minutes to wipe away any condensation that has formed on the underside, until the springform pan is lukewarm to the touch, about 1 1/2 hours total.
Remove the baking sheet and refrigerate the cheesecake uncovered until it’s chilled, at least 4 hours. (The cheesecake can be kept in the refrigerator for up to 3 days, covered with plastic wrap once completely chilled.) Meanwhile, make the strawberry sauce.
For the strawberry topping:
Place the strawberries and sugar in a medium, nonreactive saucepan and stir until the berries are coated in sugar.
Mash with a potato masher until about half of the strawberries are completely smashed but some medium-sized chunks remain, about 1 minute.
Place the pan over high heat and cook, stirring occasionally, until bubbles form along the pan’s edge, about 5 minutes.
Skim any foam from the surface of the sauce with a spoon and discard. Add the lemon zest and juice, stir to combine, and bring to a full boil, cooking until foam coats the surface, about 2 minutes. Remove from the heat and skim and discard the foam.
If the sauce needs thickening, whisk the measured water and cornstarch in a small bowl until combined and no lumps remain. Return the pan to medium heat, bring the strawberry mixture to a boil, and add the cornstarch mixture a little bit at a time, whisking frequently, until the sauce has thickened to the desired consistency.
Remove from the heat. Let the sauce cool to room temperature. Transfer to a container with a tightfitting lid and refrigerate until chilled or up to 3 days.