01 -
Place cream cheese in a stand mixer bowl (or large bowl if using an electric hand mixer). Let it sit until softened, about 1 hour.
02 -
Coarsely chop semisweet chocolate. Heat heavy cream in a microwave-safe bowl until very hot and bubbling gently, 40 seconds to 1 minute. Add chocolate to the hot cream, ensuring it is fully covered. Let it sit for 1 minute, then stir until smooth and combined.
03 -
Add powdered sugar, light brown sugar, vanilla extract, and kosher salt to the softened cream cheese. Use the whisk attachment on medium speed to beat until the mixture is combined and the sugar is dissolved, about 1 minute.
04 -
Reduce mixer speed to medium-low and slowly pour in cold heavy cream. Increase speed to medium-high and beat until stiff peaks form, scraping down the bowl as needed, about 1 minute.
05 -
Add creamy peanut butter and beat on medium-low speed until fully incorporated and fluffy, about 30 seconds. The mixture may appear broken initially but will smooth out.
06 -
Divide the mousse evenly into 4 serving vessels (about 3/4 cup each) such as coupes, jars, or ramekins. Smooth the tops gently with the back of a spoon.
07 -
Stir the ganache well and spoon about 2 tablespoons over each mousse portion. Swirl the serving dish to create an even layer without disturbing the mousse. Adjust the ganache quantity based on the serving vessel used.
08 -
Top each portion with chopped roasted peanuts. Refrigerate for at least 4 hours or up to overnight until well chilled and set. Let sit at room temperature for 5 to 10 minutes before serving.