Prepare Ice-Cream Mixture: Line a 20 x 30 cm slice pan with plastic wrap. In a large bowl, combine softened vanilla ice-cream, frozen raspberries, mixed nuts, dark chocolate, craisins, orange zest, and sea salt. Stir until well-mixed, then spoon into the pan and smooth out the top. Cover and freeze for 3-5 hours or overnight until firm.

Melt White Chocolate: Place white chocolate melts in a microwave-safe bowl. Heat in 15-second intervals, stirring in between until the chocolate is completely smooth and melted.

Decorate Biscuits: Arrange 12 chocolate ripple biscuits on a tray. Drizzle melted white chocolate on each biscuit and quickly add mini red M&M’s and spearmint leaves for a festive touch. Let them set until the chocolate becomes firm.

Assemble Sandwiches: Carefully flip the frozen ice-cream mixture onto a clean cutting board, remove the plastic wrap, and cut out 12 rounds using a cookie cutter. Place each round on the undecorated biscuits, then cover with the decorated biscuits to create delicious sandwiches. Serve immediately for a delightful treat!