Step 1: Preheat your oven to 350°F (175°C). Wrap the outside of a 9-inch springform pan with heavy-duty aluminum foil to prevent water from seeping in during the water bath. Set aside.
Step 2: For the crust: In a medium bowl, combine graham cracker crumbs, ground pistachios, and 1/4 cup granulated sugar. Pour in melted butter and mix until well combined and moist. Press the mixture evenly into the bottom of the prepared springform pan. Bake for 10 minutes. Remove from oven and let cool slightly.
Step 3: Reduce oven temperature to 325°F (160°C).
Step 4: For the filling: In a large bowl, beat softened cream cheese with an electric mixer on medium speed until smooth. Gradually add 1 1/4 cups granulated sugar and flour, beating until just combined and smooth, scraping down the sides of the bowl as needed.
Step 5: Beat in vanilla extract and almond extract (if using). Add eggs one at a time, beating on low speed after each addition just until incorporated. Do not overmix. Stir in the sour cream until just combined.
Step 6: Pour the cheesecake filling over the cooled crust in the springform pan. Place the springform pan inside a larger roasting pan. Carefully pour hot water into the roasting pan, coming about halfway up the sides of the springform pan.
Step 7: Bake for 60-70 minutes, or until the edges are set and the center still has a slight jiggle. Turn off the oven, crack the door open slightly, and let the cheesecake cool in the oven for 1 hour. Remove from the oven and water bath, and cool completely on a wire rack. Once cooled, cover and refrigerate for at least 6 hours, or preferably overnight.
Step 8: For the cherry topping: In a medium saucepan, combine cherries, 1/4 cup granulated sugar, cornstarch, water, and lemon juice. Cook over medium heat, stirring constantly, until the mixture thickens and comes to a gentle boil (about 5-7 minutes). Remove from heat and let cool completely.
Step 9: Once the cheesecake is chilled, carefully remove the sides of the springform pan. Pour the cooled cherry topping over the cheesecake. Garnish with additional chopped pistachios, if desired. Slice and serve cold.