Prepare the Tiramisu Filling:

• In a large mixing bowl, whisk together the mascarpone cheese, heavy cream, powdered sugar, vanilla extract, coffee liqueur (if using), and brewed coffee until smooth and creamy.

Add the Crumbs:

• Stir in the graham cracker crumbs (or ladyfinger crumbs) until the mixture is thick and holds together.

Form the Truffles:

• Using your hands or a spoon, scoop small portions of the mixture and roll them into balls, about 1 inch in diameter. Place the truffles on a baking sheet lined with parchment paper.

Chill the Truffles:

• Place the truffles in the refrigerator to chill for at least 1 hour, or until they are firm and set.

Dip in Chocolate:

• Once the truffles are chilled, melt the semi-sweet chocolate in a microwave-safe bowl or over a double boiler.
• Dip each truffle into the melted chocolate, coating it evenly, and return it to the parchment-lined baking sheet.

Coat with Cocoa Powder:

• After the chocolate hardens slightly, sift cocoa powder over the truffles for a classic tiramisu finish. Alternatively, you can roll them in the cocoa powder immediately after dipping in chocolate for a more intense cocoa flavor.

Serve:

• Once the chocolate has fully set, serve the truffles chilled. They can be stored in an airtight container in the fridge for up to a week.