Step 1: Prepare the Crust

1. Preheat the oven to 325°F (163°C). Line a muffin tin with cupcake liners.
2. In a food processor, pulse the pistachio cookies or graham crackers until fine crumbs form.
3. Transfer the crumbs to a bowl and mix with granulated sugar and cinnamon.
4. Add the melted butter and stir until the mixture resembles wet sand.
5. Spoon about 1 tablespoon of the crust mixture into each cupcake liner and press firmly using the back of a spoon.
6. Bake for 5 minutes, then remove from the oven and let cool while preparing the filling.

Step 2: Make the Cheesecake Filling

1. In a large bowl, beat the softened cream cheese and sugar until smooth and creamy (about 2 minutes).
2. Add the egg, mixing until just combined. Avoid overmixing to prevent air bubbles.
3. Stir in the sour cream, heavy cream, and vanilla extract, mixing until smooth.
4. Add the pistachio paste (or finely ground pistachios) and mix until fully incorporated. If desired, add a few drops of green food coloring for a more vibrant pistachio hue.
5. Divide the cheesecake filling evenly among the cupcake liners, filling each about ¾ full.

Step 3: Bake the Mini Cheesecakes

1. Bake for 15-18 minutes, or until the centers are set but still slightly jiggly.
2. Turn off the oven and let the cheesecakes sit inside with the door slightly open for 10 minutes to prevent cracking.
3. Remove from the oven and let cool completely at room temperature. Then, transfer to the refrigerator and chill for at least 3 hours (or overnight for best results).

Step 4: Prepare the Topping

1. In a mixing bowl, whip the heavy cream, powdered sugar, and vanilla extract until stiff peaks form.
2. Transfer the whipped cream to a piping bag and pipe onto the chilled cheesecakes.
3. Garnish with crushed pistachios for added texture and visual appeal.

Step 5: Serve & Enjoy!

1. Remove the cheesecakes from the cupcake liners and place them on a serving platter.
2. Enjoy these creamy, nutty, and delicious mini pistachio cheesecakes!