Preheat oven to 350 degrees. Prepare a 7 x 3-inch push pan or spring form pan by greasing the bottom and sides with butter then lining them separately with parchment paper.

In a small bowl, combine the graham cracker crumbs, granulated sugar, brown sugar, and melted butter. 

Pour the crust mixture into the pan and press into place. Come up the sides barely (¼ to ½ an inch at most). Place the pan in the oven and bake for 10-12 minutes or until the crust becomes fragrant. Remove the pan from the oven and allow to cool completely before filling.

In a small bowl, combine the granulated sugar, cornstarch, and salt. Set aside.

Using a hand mixer or stand mixer, beat the cream cheese until well mixed and fluffy. Add the sugar mixture and mix until combined. Next, add the vanilla and sour cream. Continue to mix until combined but don’t over mix.

Add the 2 eggs, one at a time, mixing between each addition. Last, use a spatula to fold in the melted chocolate. Pour the filling into the cooled crust.

Place the raspberries and sugar into a food processor and pulse until a puree forms. Pour the mixture through a mesh sieve or strainer to remove seeds.

Drizzle or dot the raspberry puree over the top of the filling, and use a sharp knife or toothpick to swirl the mixture into the cheesecake batter.

Cover the cheesecake loosely with foil.

Place a trivet in the bottom of the Instant Pot along with 2 cups of water. Use a foil sling to lower the cheesecake onto the trivet.

Close the lid and set to sealing. Use the manual/pressure cook button to adjust the time to 28-35 minutes (depending on pan **See Notes and/or post). After the time is up, allow a full natural release before opening the lid. Carefully remove the cheesecake from the Instant Pot and set on a cooling rack and remove foil. 

Allow to cool at room temperature for 1 hour before transferring to the refrigerator. The cheesecake needs to cool/set in the refrigerator for an additional 2-4 hours before serving.

Top with whipped cream, white chocolate shavings, or fresh raspberries before serving. Keep refrigerated for up to 3 days.