Separate the egg yolks from the whites while your eggs are still cold; it’s much easier this way. Store the whites in a jar in the fridge (great for omelets!) and put the yolks in a little dish; set aside.

Place the empty mousse cups in the fridge to chill. This is especially helpful if you’re making the mousse on a hot day in a kitchen without AC, like I did.

Melt the chocolate in a medium, microwave safe bowl. Place bowl in microwave for 30 seconds, then remove and stir. Place bowl back in the microwave for another 30 seconds, then remove and stir melted chocolate until smooth. If there are small lumps, keep stirring until everything is smooth. Transfer melted chocolate to a large mixing bowl and set aside to cool slightly.

In a small saucepan, combine the egg yolks, espresso powder, 4 tablespoons of the sugar, and ¾ cup of cream, and whisk. Don’t worry if the ingredients don’t all mix together perfectly or if your espresso powder clumps; it will all come together soon.

Heat the egg mixture on the stove over medium-high heat, stirring constantly with a spatula (and I mean constantly) until the mixture has thickened slightly and lightly coats the back of the spatula—only 2-3 minutes. DO NOT LET THE MIXTURE SIMMER OR BOIL.

Place a fine mesh strainer on the large bowl containing the melted chocolate. Slowly pour the heated egg mixture through the strainer and into the melted chocolate.

Whisk the egg mixture and melted chocolate together until combined. (Note: the chocolate may seize up a bit when you pour the hot egg mixture in. Don’t worry—just keep whisking and it will all come together.

Add the vanilla extract and whisk lightly to combine.

When everything is combined, the result should look like luscious brownie batter. Place the bowl uncovered into the fridge to cool completely for about 30 minutes. It should become cool, but not solidified.

Once the chocolate mixture has cooled, take a clean large bowl and pour the remaining 1 ¼ cups cream and 2 tablespoons of sugar in it. Use an electric handmixer or a KitchenAid stand mixer fitted with the whisk attachment to whip the cream until stiff peaks form. With the stand mixer, this will only take 1-2 minutes on the highest setting, but if you’re using a handmixer, it may take close to 5 minutes.

Fold the whipped cream into the chocolate mixture in three batches until thoroughly combined.

Divide the mousse between the chilled serving cups. Cover with plastic wrap and place filled mousse cups back in the fridge to chill for another 30 minutes, or overnight.

When it comes time to serve, place a dollop of whipped cream on top of the mousse. You could also sprinkle on some chopped nuts or shaved chocolate if you want to be really fancy.