Make Cherry Jam: Add cherries and water to a saucepan over medium heat and cook for 3-5 minutes until cherries soften and release their juice. Stir in chia seeds and cook for an additional 5 minutes, stirring occasionally. Remove from heat and allow to cool.
Make Chocolate Mousse: Melt cacao butter in a heatproof bowl using the Bain Marie method. Once melted, set aside to cool. In a blender, combine soaked cashews, almond milk, maple syrup, cacao powder, and vanilla extract. Blend until smooth. With the blender running, slowly add the melted (but cooled) cacao butter until fully incorporated.
Assemble Mousse Cups: Divide the mousse mixture into 12 mini muffin cups (preferably using a silicone tray). Spoon the cherry jam on top of each mousse cup and freeze for at least 4 hours.
Chocolate Coating: Melt the chocolate in a heatproof bowl using the Bain Marie method. Remove mousse cups from the freezer and gently remove them from the silicone mold. Dip each mousse cup into the melted chocolate using two forks, allowing the excess chocolate to drip off. Place dipped mousse cups onto a tray lined with baking paper.
Set and Store: Refrigerate for 1 hour to set. Store mousse cups in an airtight container in the fridge for up to one week or in the freezer for up to one month