If making from scratch, prepare and bake your tartlet shells up to 3 days in advance. Let them cool completely before filling. Store-bought shells work perfectly too.

In a small saucepan over low-medium heat, combine the cream, brown sugar, and granulated coffee. Stir until fully dissolved.

Remove from heat just as small bubbles begin to form.

Add the chopped chocolate to the cream mixture. Swirl gently to submerge most of the chocolate. Let sit for 1 minute.

Stir until smooth and glossy.

Cool for 10 minutes at room temperature.

Spoon about 1 tablespoon of ganache into each tartlet shell.

Refrigerate for 1 hour until set.

In a medium bowl, whip the thickened cream until stiff peaks form—be careful not to overwhip.

In a separate bowl, beat mascarpone, caster sugar, and vanilla until just combined.

Gently fold in the whipped cream in thirds, keeping the mixture light and fluffy.

Transfer the mascarpone cream into a piping bag.

Pipe a generous dollop over the chilled ganache layer in each tartlet.

Dust with cocoa powder and top with a coffee bean if desired.