Step 1: Prepare the Berry Swirl

1. Cook the Berries: In a small saucepan, combine the frozen berries and sugar over medium-low heat. Stir occasionally for 5–10 minutes, until the berries break down and become syrupy.
2. Puree and Strain: Blend the mixture in a food processor or chopper until smooth, then strain through a fine-mesh sieve to remove seeds. Set aside to cool completely.

Pro Tip: Allow the berry sauce to cool fully before swirling into the cheesecake filling to prevent it from thinning the batter.

Step 2: Make the Crust

1. Crush the Crackers: Place the crackers and sugar (if using) in a food processor. Pulse until finely ground.
2. Combine with Oil: Mix the crumbs with olive oil (or melted butter for brownie thins crust) until evenly moistened.
3. Line the Pan: Lightly grease a mini-cheesecake pan. Add about 1 tablespoon of crumb mixture to each well, pressing firmly with a spoon or tamper to form an even crust.

Common Mistake: Avoid over-packing the crust, as it can harden excessively during baking.

Step 3: Make the Cheesecake Filling

1. Beat the Cream Cheese: Preheat the oven to 300°F (150°C). In a large bowl, mix the softened cream cheese, granulated sugar, and cornstarch using a paddle attachment on medium speed until creamy and smooth.
2. Add the Eggs: Blend in the eggs one at a time. Scrape down the bowl after each addition to ensure a smooth batter.
3. Incorporate Liquids: Stir in the heavy cream, lemon extract (if using), vanilla bean paste, and salt. Mix until just combined.

Pro Tip: Do not overmix the batter, as it can incorporate air and cause the cheesecakes to crack during baking.

Step 4: Assemble the Cheesecakes

1. Fill the Wells: Divide the cheesecake filling evenly among the crust-lined wells, filling nearly to the top.
2. Add the Swirl: Drizzle 1 teaspoon of the cooled berry sauce on top of each cheesecake. Use a toothpick or skewer to create a marbled pattern by gently swirling the sauce into the batter.

Step 5: Bake and Cool

1. Bake: Place the pan in the oven and bake for 22–25 minutes, or until the edges are set but the centers still jiggle slightly.
2. Cool: Remove the cheesecakes from the oven and let them cool in the pan for 20 minutes. Then, transfer the pan to the refrigerator to chill for at least 2 hours, or until fully set.

Common Mistake: Overbaking the cheesecakes can cause cracks; they should be slightly jiggly in the center when removed from the oven.

Step 6: Serve

1. Once chilled, carefully remove the cheesecakes from the pan.
2. Top with fresh raspberries, a drizzle of remaining berry sauce, whipped cream, or a sprinkle of lemon zest for garnish. Serve cold and enjoy!