Prepare the Crust:

In a bowl, mix the graham cracker crumbs, sugar, and melted butter until evenly combined. Press the mixture firmly into the bottom of a 9-inch springform pan to form the crust. Refrigerate while preparing the filling.

Make the Raspberry Ripple:

In a saucepan, combine the raspberries, sugar, and lemon juice. Cook over medium heat until the raspberries break down and release their juices (about 5 minutes). Add the cornstarch slurry and cook for an additional 1–2 minutes, stirring until the mixture thickens. Remove from heat and let cool completely.

Assemble the Ice Cream Layer:

In a large mixing bowl, stir together the softened vanilla ice cream, heavy cream, and vanilla extract until smooth. Pour half of the ice cream mixture over the chilled crust, spreading it evenly.

Add the Raspberry Ripple:

Spoon dollops of the cooled raspberry sauce over the ice cream layer and gently swirl using a knife or skewer to create a ripple effect. Pour the remaining ice cream mixture on top and repeat the ripple process with more raspberry sauce.

Freeze:

Cover the pan with plastic wrap or foil and freeze the cake for at least 6 hours or until firm.

Garnish and Serve:

Remove the cake from the springform pan and transfer to a serving plate. Garnish with fresh raspberries, whipped cream, or white chocolate shavings for an elegant touch. Slice and serve immediately!