Important note: To make sure your mousse is smooth, the silken tofu should be at room temperature or slightly warm when blended with the chocolate. Cold tofu may result in a grainy mousse. If you're in a hurry, you can place the silken tofu in a microwave-safe bowl and pop it in the microwave for a minute or so to warm it up a little.
Melt chocolate: Add the semisweet chocolate to a microwave-safe bowl. (If using a chocolate bar, give it a coarse chop first to help it melt evenly.) Microwave in 30 second increments, stirring in between, until completely melted. Set aside to cool slightly while you blend the other ingredients.
Blend tofu: Add the silken tofu to your food processor. Sift in the powdered sugar and cocoa powder to ensure no lumps. Then add the vanilla bean paste, instant coffee (if using), and pinch of salt. Blend until completely smooth, scraping down the sides of the food processor as needed.
Add in chocolate: Add the melted chocolate into the blended tofu mixture and blend until incorporated and smooth, scraping down the sides of the food processor as needed.
Adjust to taste: Give the mousse a taste and add more sweetener or salt if you like.
Chill: Transfer the mousse into a sealable container, or into a few containers with lids for individual portions). Refrigerate for at least 2 hours — but preferably overnight — to allow it to set. The flavor will also improve as the mousse chills, so please be patient!
Enjoy: I love serving this mousse with a dollop of coconut whipped cream, chocolate shavings, and a handful of fresh berries. For special occasions, I will garnish with a sprig of fresh mint.