Place parchment paper or silicone muffin liners in a 12-cup muffin tin and set aside.
Melt chocolate using the double-boiler method: Bring a small saucepan of water to a simmer and place a heatproof bowl over the top. Make sure the simmering water isn't touching the bowl. Add the chocolate and the coconut oil to the bowl and slowly melt and stir the chocolate, whisking together at the end. Alternatively you could melt the chocolate in the microwave at 20 second intervals, whisking in between until it's fully melted.
In a small bowl combine almond butter, pumpkin puree, pumpkin pie spice, and sweetener.
Place 2 teaspoons of chocolate into each of the molds with a spoon and gently push the chocolate 1/3 of the way up the sides of the parchment paper. Place in the freezer to harden for 10 minutes.
Remove from freezer and drop in about 1 tablespoon of pumpkin mixture into the center of the chocolate and smooth down.
Top the pumpkin mixture with 2 teaspoons melted chocolate and let sit for a few minutes before sprinkle with coarse sea salt.
Store in the refrigerator for 1 week or in the freezer for 3 months.