Line a standard muffin tin with 12 muffin liners, then melt the chocolate chips and coconut oil together. You can do this in a microwave, or in a double boiler by filling a small pot with an inch of water. Place a heat-safe bowl snugly on top of the pan, and add the chocolate chips and tablespoon of coconut oil to the bowl. The steam from the boiling water below will gently melt the chocolate. Stir until the chocolate is smooth.
Add a teaspoon of the melted chocolate into the bottom of each muffin liner. Repeat until all 12 cups are filled with the bottom layer of chocolate, then tilt the pan so the chocolate will swirl around each muffin cup, going up the sides of the muffin liner slightly. This will help give your almond butter cups a nice edge. Place the pan on a flat surface in your freezer to let the chocolate set. Leave the remaining melted chocolate in the bowl on the saucepan, so it will stay warm and melted. (The stove does not need to remain on, though.)
While the chocolate is setting in the freezer, mix the almond butter and maple syrup together in a small bowl. Add a pinch of salt, if you are not using salted almond butter, to help the almond flavor pop.Remove the pan from the freezer. Scoop the almond butter mixture using a heaping teaspoon, then roll it between your hands to form a ball. Flatten the ball to make a disc, then place it on top of the hardened chocolate layer in the muffin cup. Repeat with the remaining almond butter mixture, until all of it has been used up and the muffin cups are each filled with almond butter. If you have extra almond butter mixture to use up, you can press the excess into any cup that might seem less-full than others.
Add a teaspoon of melted chocolate to the top of each almond butter cup, and use the spoon to spread it around so the chocolate totally covers the top. Sprinkle some flaky sea salt on top of the melted chocolate, if you'd like a salted top. Repeat until all of the almond butter cups are covered in chocolate, then place the pan in the freezer to let the chocolate set, at least 30 more minutes. Then transfer them to the fridge, so they don't become too hard to bite into.
As soon as the chocolate is set, the dark chocolate almond butter cups are ready to serve. The coconut oil will make these melt in a warm room, so be sure to keep them stored in an airtight container in the fridge for the best texture. You can store almond butter cups in an airtight container in the fridge for at least 1 month. Or, you can keep them in the freezer for up to 3 months. (The texture will be much harder when they are frozen, so be cautious when biting into a frozen-solid one.)
Notes
Nutrition information is for 1 of 12 large almond butter cups. This information is automatically calculated, and is just an estimate, not a guarantee.Use refined or expeller pressed coconut oil, if you want zero coconut flavor in these.