In a small saucepan over low heat melt cacao butter. Add maple syrup, cacao powder and vanilla and whisk to combine. Remove from heat.
Line a mini muffin pan with liners. Start with 12 liners - pour chocolate to the halfway point in each liner. Drop a heaping ½ tsp peanut butter in each cup. Fill to top with remaining chocolate. May be able to fill 1 or 2 more cups.
Freeze peanut butter cups for 10 minutes. Top each cup with a small pinch of sea salt. Store chocolates in the freezer in an airtight container.
Recipe by Good Thyme Kitchen at https://www.goodthymekitchen.com/vegan-peanut-butter-cups/