In a microwave-safe bowl, combine chocolate and cream. Heat the mixture in 20-second increments on medium to low power, stirring between intervals. Once the chocolate is mostly melted, continue stirring until it's completely smooth.

In a mixing bowl, blend your chosen crushed cookies, finely chopped toasted hazelnuts, cocoa powder, and the chocolate mixture. Mix thoroughly until it forms a cohesive, sticky dough.

Shape the dough into small balls (around 1 tablespoon each) using your hands or a small cookie scoop. Roll each ball in the plate of finely chopped hazelnuts to coat them. You can also use a cookie ring for a uniform shape. Create a gentle indentation in the center of each cookie with your thumb or the back of a teaspoon—this is where the caramel filling will rest.

Homemade Salted Caramel (optional):In a saucepan over medium heat, melt the caster sugar while constantly stirring until it turns into a rich amber colour. Add the unsalted butter and stir until fully combined. Slowly pour in the heavy cream while stirring vigorously. Be cautious as the mixture may bubble. Finally, stir in the salt. Allow the caramel to cool slightly before using it for filling.

Transfer the shop bought or homemade salted caramel into a piping bag. Carefully pipe the caramel into the indentations you created on the cookies. Allow the caramel to set and chill for about 30 minutes.

In short bursts, microwave the remaining chocolate until it's fully melted and velvety. Transfer the melted chocolate into a piping bag.

Drizzle the melted chocolate onto the cookies, covering the caramel-filled centers. Refrigerate the cookies until the chocolate sets and becomes firm.

Once the chocolate is set, your delectable no-bake caramel-filled hazelnut chocolate cookies are ready to be savoured! These can be stored in a Tupperware container for 5 days. For optimal deliciousness, I recommend letting them sit at room temperature for about 20 minutes before enjoying.