Combine strawberries, lemon juice, vanilla extract, and sugar in a medium pot.
Stir everything together and bring to simmer over medium heat. Cover and cook strawberries over medium-low heat until completely softened.
In a measuring cup, mix corn starch with a little cold water and stir it into the strawberry filling. Stir slowly and cook for a couple of minutes, until the mixture thickens.
Take it off heat and let it cool completely before using in the cheesecake.
If not using the strawberry filling right away, transfer it into a food storage container with a lid and refrigerate for a day or two.
Make sure to pull cream cheese out of the refrigerator about an hour before starting to make the cheesecake to let it soften.
Grease a 9-inch springform with some cooking spray.
Use a paddle attachment. Beat softened cream cheese for a couple of minutes, until soft and fluffed. Scrape sides and bottom of the bowl and beat for a few more seconds.
Add sour cream, sugar, and vanilla extract and beat for about another minute.
Add cooled strawberry filling and beat until the filling is just incorporated throughout.
Take cream cheese mixture out of the mixer bowl and into a separate large mixing bowl.
Clean out the electric mixer bowl before making whipped cream. Switch to a whisk attachment.
Add cold heavy whipping cream into the mixer fitted with a whisk attachment and start whisking on low speed. Gradually raise the speed to medium-high as you slowly pour in sugar. Whisk until stiff peaks form.
Fold cream cheese mixture and whipped cream together until completely combined.
Spoon cheesecake filling all over the crust and then use a spatula to spread it evenly.
Cover the springform pan with plastic wrap and refrigerate overnight, or for at least 6 hours.
Once cheesecake is cooled and set, spread remaining strawberry topping on top.
To serve: Run a greased butter knife along the edges of the cheesecake to separate it from the pan before opening the springform sides.