For the caramel:

Add the sugar to a pot over medium heat and cook without stirring. The sugar will start browning in the center and begin to melt. Continue cooking on medium to low heat until the sugar is melted and the caramel is amber in color. Keep the heat on low while you stir in the butter. Once the butter is stirred in, add the cream a little at a time, stirring constantly. After the cream is completely mixed in, the caramel is ready. Remove from heat and pour into a jar. Allow to cool to room temperature before placing the jar in the fridge until ready to use. 

(Observation: my caramel was turning brown in the center and not melting enough around the edges. It might be due to the coarse-grained sugar or the way the flame was centered on the pot. I began to freak-out and added the butter before the sugar was completely melted. Also, the butter was cold, so I think I will use room-temperature butter next time. All this to say, that when I added the butter, some of the sugar crystallized and turned into sugar-rocks. At this point I figure I might as well go for it and add the cream. To save the caramel, I strained out the sugar rocks while pouring the remainder of the caramel into the jar. I am so happy I didn’t throw the caramel out, because regardless of the sugar rocks needing to be removed, what remained was the most delicious and creamy caramel I have ever had! My daughter reminded me that on British Bake-Off the contestants often struggle with caramel, so I didn’t feel too terrible about my mishap.) 

For the Chocolate Mousse:

In a small pot, bring the cream to a slight boil. Place the chocolate in a glass bowl and pour the hot cream over it. Let it rest for about a minute before whisking the cream and chocolate to create a smooth consistency. (Tip: if the chocolate is not completely melted after you have whisked it, place the glass bowl in the microwave for 15 seconds and whisk it again.) 

Beat the egg yolks into the chocolate ganache. 

In a separate bowl, beat the egg whites with a pinch of sea salt. While beating, add 1 Tbsp of sugar and beat for 30 seconds before adding the second Tbsp of sugar. Beat another 30 seconds and then add the final Tbsp of sugar. Beat another 30 seconds. 

Fold the egg whites into the chocolate ganache using a rubber spatula. Fold over and under making figure eights until the chocolate and egg whites are completely incorporated. 

Divide the mousse into 6 serving glasses and keep refrigerated for a few hours to set. When ready to serve, top the mousse with a spoonful or two of caramel.