Preheat electric griddle to medium heat (or about 350 degrees F / 176 C), or a large skillet on the stove stop. You want the surface to be hot but not screaming hot – oil shouldn’t smoke when it makes contact with the surface.
To a large mixing bowl add flaxseed and water and let set for a minute or two. Then add melted coconut oil, agave nectar (or honey/maple syrup), baking soda, baking powder, salt, vanilla extract and whisk to combine. Add almond milk (starting with lesser end of range and adding a touch more if needed) and whisk again until well combined.
Next add oat and gluten free flour and stir until just combined. Taste and see if it needs more agave. I added a bit more.
Divide batter in half and add cocoa powder to one bowl and peanut butter to the other. Mix until just combined. Add more almond milk if PB made it too thick. You want a pourable batter that's not "gloppy."
Once the griddle is hot, lightly grease and spoon on scant 1/4 cup measure of chocolate batter, then scant 1/4 cup of peanut butter in the center. Cook until the edges appear dry and bubbles form on top, then carefully flip. Cook for another 2-ish minutes on the other side. Will make 5-6 pancakes.
Divide between serving plates and top with a peanut butter cup split in half or a Tbsp or two dark chocolate chips.
Dig in and enjoy. Will reheat fine in the microwave the next day.
Notes
*If not vegan, you can sub 1 chicken egg in place of 1 Tbsp (7 g) flaxseed meal and 2 ½ Tbsp (37 ml) water. *Nutrition information is a rough estimate for 2 pancakes each with 1/2 a peanut butter cup.