Cut a circle of parchment paper to fit the bottom of a 7-inch springform pan.
Stir butter and sugar into graham cracker crumbs until it resembles the consistency of wet sand. Press into bottom and up sides of the pan.
Place crust in the freezer while making the filling.
In a large bowl, beat cream cheese until fluffy. Add sugar, flour, lemon zest, lemon juice, and sour cream. Mix well.
Add in eggs, one at a time, mixing after each addition. Pour filling into crust.
Process raspberries and sugar in the food processor until mixed.
Drop spoonfuls of raspberry mixture over surface of cheesecake. Using a butter knife, swirl raspberry mixture.
Cover cheesecake with foil, sealing edges. Poke a small hole in the center of foil to release steam.
Add 1 c. water to the bottom of your Instant Pot.
Place cheesecake on the trivet that comes with the Instant Pot. Lower it into the pot.
Seal your Instant Pot according to the pot directions. Set to high pressure and cook for 55 minutes. When time is up, allow pressure to release, then manually release any remaining pressure. Remove cheesecake and allow to cool on a wire rack after removing the foil.
To make the lemon topping, lightly mix eggs to combine whites and yolks.
In a medium saucepan, combine eggs, sugar, lemon zest, and lemon juice. Cook over medium-low heat, stirring constantly with a wooden spoon until the mixture becomes creamy. Lower heat to low, then continue cooking until the mixture thickens and coats the back of the wooden spoon. Remove from heat and stir in butter until blended.
Cool lemon topping mixture, then spread over top of cooled cheesecake. Arrange fresh raspberries on top of the lemon topping.
Chill cheesecake thoroughly before slicing. Store any leftovers in the refrigerator.