In a double boiler or saucepan over low heat, gently melt the coconut oil with cacao butter.
Remove from heat and add in swetener, collagen, cardamom. vanilla, and salt. Continue stirring until smooth.
Distribute the walnuts evenly between 8 mini muffin molds. Pour the melted chocolate mixture equally each muffin well.
Place in the freezer for 30 minutes to chill. Once set, they will pop out easily. Tip upside down and bang on the counter to release or take a knife, run around the edges, and separate the chocolate from the mold.