Preheat the oven to 350 degrees. Butter and lightly flour the bottom and sides of a 9″ springform pan. Line a baking sheet wide enough to hold the springform pan with parchment paper.
In a food processor or blender (I have a Blendtec), pulse cookies until they are crumbs. Add the melted butter and pulse again until combined. Press the mixture into the prepared springform pan, creating an even layer on the bottom and halfway up the sides. Using a flat-bottomed glass cup with straight sides is helpful.
Bake the crust for 10 minutes. Remove from the oven and allow to cool on a wire rack.
In a large bowl, beat the cream cheese on low speed until creamy, taking care not to whip and add air to the cheese.
Add the sugar and beat until smooth.
Scrape down the sides and add one egg at a time, beating on low until the egg is fully incorporated.
Add the extract, beating on low until smooth and creamy. The batter will be on the thicker side.
Remove one cup of cheesecake mixture and set aside.
In a medium saucepan, whisk together eggs, sugar and key lime zest.
Add key lime juice and cook until the mixture is thick, then simmer gently for a few seconds.
Scrape the filling into a fine mesh sieve over a bowl and strain, pushing through filling as necessary.
Stir in vanilla.
Combine curd with reserved one cup of cheesecake mixture.
Put the springform pan on a baking sheet and pour the plain batter into the baked crust.
Gently scoop the curd mixture over the top, spreading evenly yet leaving a 1″ ring around the edges.
If desired, marble the two layers together using a dull knife, taking care not to cut the crust.
Cover the springform pan with another baking sheet and bake the cheesecake for 30 minutes.
Remove the baking sheet “lid” and continue to bake the cheesecake for 20-25 minutes, until the edges are set but the center is still jiggly like Jell-O.
Combine the topping ingredients in a bowl and spread evenly over the baked cheesecake.
Wash and thinly slice strawberries. Gently place strawberries on top of the sour cream layer.
Return the cheesecake to the oven and bake for 5 minutes.
Remove the cheesecake from the oven and allow to cool on a wire rack for 1-2 hours.