Begin by melting the chocolate. You can do this in a bowl over a pot of water, or in the microwave. While the chocolate is melting, prepare the espresso.
When the chocolate is nearly melted, prepare the egg whites. In a medium bowl, combine the egg whites with the sugar. Whip using a hand held mixer or using a stand mixer, until the egg whites form stiff peaks. This can take about 2-5 minutes. Room temperature egg whites will give better volume, and a very clean bowl will allow them to fluff up faster. (Any residual fat that might be left in a mixing bowl will make it harder for the egg whites to fluff up)Once the egg whites are hold stiff peaks, set them aside. Now your chocolate should be melted.
When the chocolate is melted, make sure the espresso is still quite hot, and pour it into the chocolate. Stir with a whisk quickly to emulsify the coffee and chocolate. Add your salt and Almond extract now as well.
One at a time, add the egg yolks into the chocolate mixture, whisking quickly and thoroughly after each one.
Finally you need to combine the fluffy egg whites with the denser chocolate mix. To begin, you will need to make the two mixes have a more similar texture. To do that you will "sacrifice" about 1 cup of your fluff to the chocolate. Simply scoop out the 1 cup from the egg whites, and stir it into the chocolate. you're not folding here, just stirring it in, to loosen the chocolate.
Now in three parts add the whites into the chocolate, and gently fold it together. Once the first part is nearly mixed in, add the next and repeat.
Once your mix is homogeneous divide it into your serving dishes, cover with plastic, and chill in the fridge for at least one hour before serving. These will store in your fridge for up to a week.