Place 1 cup of raspberries and sugar into medium sauce pan. Set over medium heat and stir until raspberries turn into liquid. Bring to boil and slightly reduce heat to a simmer. Simmer until most of the liquid has evaporated, about 5-7 minutes.

Place puree in a metal sieve over a large bowl. Push puree through seeds to separate it from the seeds. Continue until all of the puree is strained and seeds remain in sieve. Set aside while we melt the chocolate.

Place bowl over sauce pan filled with water about 1/4 of the way up. Make sure bowl does not touch water. Set over medium heat. Place chocolate in bowl so that it melts slowly and stir it occasionally. Once completely melted, add raspberry puree and stir until incorporated. Let the mixture warm up again so that it's velvety smooth. Turn off heat but keep bowl on top of pan while we make whipped cream.

Add heavy cream to bowl of stand mixer fit with the beater attachment. Beat cream on high until it forms stiff peaks. Turn off mixer and remove bowl from stand.

Grab bowl with chocolate mixture. Add 1/4 teaspoon of vanilla extract. Stir with spatula to combine. Add 1/3 of whipped cream to chocolate mixture and gently fold in until incorporated. Add chocolate mixture to the rest of the whipped cream and gently fold together. You don't want the whipped cream to deflate.

Scoop chocolate mousse into 4 ramekins or small bowls. Refrigerate for 1 hour until set. Top with raspberries and sprinkle with powdered sugar.