In a medium saucepan, whisk together fresh lemon juice, sugar, and eggs off heat until smooth. Place the saucepan over low heat and continuously stir the mixture until it thickens and coats the back of a spoon, about 10–15 minutes. Remove from heat, add unsalted butter, and stir until fully melted. Strain the lemon curd into a bowl and chill in the refrigerator overnight or until set.

While the lemon curd chills, preheat your oven to 350°F (175°C). Blend graham crackers into fine crumbs in a food processor. Transfer the crumbs into a mixing bowl, add softened unsalted butter, and stir until crumbly and well combined. Reserve a small portion of the crumbs for garnish later. Spread the remaining mixture evenly into the bottom of small cups, pressing down lightly to form a solid base.

In a large mixing bowl, beat room-temperature cream cheese and superfine sugar together using an electric mixer until creamy and smooth, about 3–4 minutes. Gently fold in the chilled lemon curd until well combined. In a separate bowl, whip the heavy cream until stiff peaks form. Carefully fold the whipped cream into the lemon cheesecake mixture.

Layer the Lemon Curd Cheesecake Dessert Cups by piping half of the cheesecake mousse into each prepared cup, smoothing the top for an even layer. Next, add a layer of chilled lemon curd atop the mousse. Finish with remaining mousse, using a piping bag or spoon to create a swirl on top.

Cover the dessert cups with plastic wrap and place them in the refrigerator. Chill for at least one hour to allow the flavors to meld and the mousse to set. When ready to serve, sprinkle the reserved graham cracker crumbs on top.