Classic Cheesecake-Instant Pot

1 ¼ cups graham cracker crumbs
5 tablespoons butter melted and cooled, plus additional butter for buttering the pan
1lb cream cheese, full fat-room temperature
½ cup granulated sugar
2 large eggs
¼ cup sour cream-full fat
2 teaspoons lemon zest
1 tablespoon lemon juice
½ teaspoon vanilla extract
¼ teaspoon salt
1 ½ tablespoons all-purpose flour
1/3 cup sour cream
2 teaspoons sugar

1. Generously butter the inside of a 7-inch round springform pan. Mix the graham cracker crumbs and the melted butter in a medium bowl, then pour this mixture into the prepared pan. Press this mixture evenly across the bottom and about halfway up the sides of the pan to make a crust.
2. Put the cream cheese and sugar in a food processor, process until smooth. Add the eggs one at a time, processing each until smooth. Open the machine, scrape down the inside, and add the sour cream. Cover and process until smooth.
3. Add the lemon zest, lemon juice, vanilla, and salt. Process again until smooth — and again, stop the machine and scrape down the inside. Add the flour and process for 1 minute. Pour this mixture into the prepared crust in the pan (it will rise above the crust on the sides). Do not cover the pan.
4. Pour 1 1/2 cups water into a 6-or 8-quart Instant Pot. Set a trivet in the cooker. Make an aluminum foil sling, set the filled springform pan on it, and use it to lower the pan into the pot. Fold down the ends of the sling so that they do not touch the batter in the pan. Lock the lid onto the pot. Press Pressure cook (Manual) on High pressure for 25 minutes with the Keep Warm setting off.
5. To make the sour cream topping, combine 1/3 cup sour cream with 2 teaspoons sugar in a small bowl. Set aside.
6. When the machine has finished cooking, turn it off and let the pressure return to normal naturally, about 20 minutes. Remove the lid. Use the sling to transfer the hot springform pan to a wire rack. Using a paper towel, blot off any water on top of the cake.
7. While the cheesecake is still hot, spoon the sour cream topping onto the cake and spread evenly over the top.
8. Cool the cheesecake for 15 minutes, then refrigerate for 1 hour. Cover and continue refrigerating for at least 1 more hour or up to 2 days.
9. To serve, uncover and run a thin knife between the pan and the cake. Unlatch the sides of the pan and open it to remove the cake inside. If desired, use a long, thin knife to slice the cake