Preheat your oven to 325°F (163°C). In a mixing bowl, combine graham cracker crumbs and sugar, then drizzle in melted butter. Stir until the mixture resembles wet sand. Press this mixture firmly into the bottom of paper-lined muffin cups, ensuring an even layer. Bake for 5 minutes or until lightly golden, then remove from the oven and let cool completely.

Add fresh raspberries and granulated sugar to a food processor, pureeing until smooth. Pass the raspberry mixture through a fine mesh sieve into a bowl to eliminate seeds, leaving you with a vibrant sauce. Set the raspberry swirl aside while you prepare the filling.

In a large mixing bowl, whisk together granulated sugar and flour until well combined. Add the softened cream cheese and lemon zest, blending with an electric mixer on low until smooth and creamy. Gradually incorporate eggs one at a time, mixing just until blended. Finally, add the vanilla extract and sour cream, folding gently.

Evenly distribute the cheesecake filling into each cooled muffin cup over the prepared crusts. Spoon a small amount of the raspberry sauce on top of each filled cup. Using a toothpick, gently swirl the raspberry sauce into the filling.

Place the muffin tin in the preheated oven and bake for 22-25 minutes, or until the tops are slightly puffed and the centers appear set but still slightly jiggly.

Once cooled, cover the mini cheesecakes with plastic wrap or a lid and refrigerate for at least 3 hours until fully chilled and firm. When ready to serve, carefully remove them from the muffin tins and garnish with whipped cream and fresh raspberries.