Chill your tools. Pop a mixing bowl and whisk attachments into the fridge or freezer for 10 minutes. Cold equipment helps the cream whip faster and hold air better.

Prep the raspberries. Rinse and pat dry. In a small bowl, mash 3/4 cup raspberries with the lemon juice and 1–2 tablespoons of sweetener. Set aside to let the flavors meld.

Soften the cream cheese. In a separate bowl, beat the cream cheese with a handheld mixer until smooth and fluffy, about 1 minute. Add the vanilla, a pinch of salt, and the cocoa powder.

Sweeten and smooth. Add the remaining sweetener (start with 1/4 cup, then adjust). Beat until the mixture is creamy with no cocoa lumps. Scrape the bowl to make sure everything is fully combined.

Whip the cream. In your chilled bowl, whip the heavy cream to medium-stiff peaks. It should hold shape but still look glossy. Don’t go to butter territory.

Fold it together. Add one-third of the whipped cream to the chocolate mixture and gently fold to lighten it. Add the rest in two additions, folding just until combined. Avoid overmixing to keep it airy.

Ripple in raspberries. Spoon dollops of the mashed raspberry mixture into the mousse and gently fold once or twice to create a ripple effect. You want streaks, not a uniform pink color.

Taste and adjust. Check sweetness and cocoa depth. If you like it richer, fold in 1 more teaspoon cocoa. If you want sweeter, sift in a bit more powdered sweetener and fold gently.

Portion and chill. Spoon into 4 small glasses or ramekins. Top with the remaining whole raspberries and optional chocolate shavings or cocoa nibs.

Let it set. Chill for at least 30–60 minutes. The texture firms up slightly and the flavors round out.