1. Prepare the Cookie Crust

Start by preheating your oven to 350°F (175°C) and lightly greasing a 12-cup mini tart pan or muffin tin. You can also line the tin with paper cupcake liners for easy removal.

In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy. This should take about 2-3 minutes with an electric mixer on medium speed. The creaming process is essential for creating a smooth, tender cookie crust.

Add the egg and vanilla extract to the mixture, beating well to combine. The egg acts as a binder, helping the crust hold together, while the vanilla enhances the overall flavor of the dough.

Next, in a separate bowl, whisk together the all-purpose flour and salt. Gradually add the dry ingredients to the wet ingredients, mixing just until combined. If the dough is too dry or crumbly, add a tablespoon of milk at a time until the dough comes together.

Once the dough is ready, scoop out small portions and press them into the bottom of the prepared tart pan, creating a thin, even layer in each cup. Use your fingers or the back of a spoon to press the dough into the corners of each tart cup. You can also use a fork to poke a few holes in the dough to prevent it from puffing up while baking.

2. Bake the Cookie Crusts

Place the tart pan into the preheated oven and bake for 12-15 minutes, or until the cookie crusts are golden brown and firm. Keep a close eye on the tarts towards the end of the baking time, as they can burn quickly. Once done, remove the pan from the oven and allow the crusts to cool completely in the pan.

3. Prepare the Truffle Filling

While the cookie crusts are cooling, prepare the truffle filling. In a medium saucepan, heat the heavy cream over medium heat until it begins to simmer. You’ll see small bubbles forming around the edges of the cream, but don’t let it come to a full boil.

Remove the saucepan from the heat and immediately add the chopped chocolate to the cream. Let the mixture sit for about 2-3 minutes to allow the chocolate to melt. Then, whisk the mixture gently until smooth and creamy. Stir in the butter and vanilla extract, and add a tablespoon of liqueur if desired, for an extra layer of flavor.

Once the truffle filling is smooth and glossy, let it cool slightly before filling the cooled cookie crusts. The mixture should be thick but still pourable. If it’s too runny, you can refrigerate it for a few minutes to thicken it up, but be careful not to let it harden completely.

4. Fill the Cookie Tarts

Once the cookie crusts have cooled, spoon the truffle filling into each tart shell. Fill each tart almost to the top, leaving just a small gap at the edge. The truffle filling will settle and firm up as it cools, creating a smooth, velvety surface.

After filling all of the tarts, gently tap the tart pan on the counter to settle the filling and remove any air bubbles. This ensures that the filling is evenly distributed and creates a smooth finish.

5. Chill the Tarts

Place the filled tarts in the refrigerator for at least 1 hour to allow the truffle filling to set. The truffles should become firm and smooth, holding their shape when you remove them from the pan.

6. Garnish and Serve

Once the tarts have set, you can garnish them with a variety of toppings for added flavor and visual appeal. Some great options include:

• Shaved chocolate or chocolate curls for a luxurious touch.
• A light dusting of cocoa powder for a classic look.
• Chopped nuts like pistachios, hazelnuts, or almonds for texture and flavor contrast.
• A sprinkling of powdered sugar for a festive finish.

Once garnished, the tarts are ready to serve. Arrange them on a platter or in individual serving dishes for an elegant presentation.