1. Prepare the Crust:

Preheat oven to 325°F (163°C). Line a 12-cup muffin tin with paper liners.

In a bowl, mix graham cracker crumbs, sugar, cinnamon (if using), and melted butter until well combined.

Divide mixture evenly among cupcake liners (about 1 tbsp each) and press down firmly using the bottom of a small glass.

Bake crusts for 5–6 minutes. Let cool while preparing the filling.

2. Make the Cheesecake Filling:

In a large bowl, beat softened cream cheese until smooth. Add sugar and beat until fluffy.

Beat in eggs, one at a time, mixing just until combined.

Add vanilla, sour cream, lime juice, and lime zest. Mix until smooth but don’t overbeat.

Spoon filling evenly into prepared crusts, filling each about ¾ full.

3. Bake the Cupcakes:

Bake for 18–20 minutes, until centers are just set (a slight jiggle is fine).

Cool in pan for 10 minutes, then transfer to a wire rack. Refrigerate for at least 2 hours, or overnight.

4. Make the Blackberry Topping:

In a small saucepan, combine blackberries, sugar, and lime juice.

Cook over medium heat for 5–7 minutes, stirring gently, until berries break down and the sauce thickens slightly.

Remove from heat and cool completely.

5. Assemble and Serve:

Top each chilled cheesecake cupcake with a spoonful of blackberry topping. Garnish with extra lime zest or a fresh blackberry if desired.