Preheat your oven to 350°F (175°C).
Time for the crust! In a medium bowl, toss together graham cracker crumbs and melted butter. Stir it until it looks like wet sand. Pour the crumb mixture into a 9-inch springform pan and press it firmly into the bottom and slightly up the sides. Bake in the preheated oven for just 8-10 minutes until toasted. Let it cool completely while you make the filling.
Now for the creamy magic! In a large bowl, beat your softened cream cheese with the granulated sugar until super smooth and fluffy, with no lumps.
Stir in the vanilla extract.
Add the eggs, one at a time. Beat well after each addition, just until the egg is incorporated.
Gently stir in the sour cream and the all-purpose flour. Mix just until everything is combined and the batter is smooth. Do NOT overmix at this stage!
Pour the cream cheese mixture over your cooled graham cracker crust in the springform pan.
Time for the strawberry swirl! Take spoonfuls of your strawberry puree and dollop them randomly over the top of the cheesecake batter. Grab a knife or a skewer and gently swirl the puree through the batter.
This next step is CRUCIAL for a smooth, crack-free cheesecake: the water bath! Get a larger baking pan (like a roasting pan or a 10-inch cake pan). Place your springform pan inside the larger pan. Carefully pour about an inch of hot (or boiling) water into the larger pan, around the springform pan. Make sure the water doesn't get into the springform pan!
Carefully transfer the whole setup (large pan with water and springform pan inside) to your preheated oven. Bake for 60-75 minutes. The edges should look set and slightly puffed, but the center (about a 2-3 inch circle) should still be a little jiggly. Don't wait until the center is completely firm.
Patience, my friend! Once the baking time is up, turn off the oven. Prop the oven door open slightly (you can use a wooden spoon handle). Let the cheesecake cool slowly in the oven for 1 full hour.
After its hour in the warm, turned-off oven, carefully remove the cheesecake from the oven and lift the springform pan out of the water bath. Place the springform pan on a wire rack to cool completely at room temperature. This can take another hour or two.
Almost there! Once it's completely cool, cover the springform pan loosely with plastic wrap. Chill it in the refrigerator for at least 4 hours. Overnight is even better if you can wait!
The grand finale! When you're ready to serve, release the springform pan sides. Garnish the top with beautiful, fresh strawberries. Slice with a sharp knife dipped in hot water between cuts for the cleanest slices. Enjoy your masterpiece!