Preheat your oven to 350°F and prepare a mini muffin pan by spraying the pan with cooking spray or lining them with parchment paper liners. Set aside.
Add all the ingredients except for the chocolate chips and hemp hearts to a high-speed blender or food processor and process on high until the oats and buckwheat have fully broken down and the batter is smooth and creamy this will take about 2 minutes.
Stir in the nuts or hemp hearts and chocolate chips by hand, reserving a few tablespoons to sprinkle on top.
Pour the batter into the prepared muffin cavities, filling each one until it is about 3/4 full. Sprinkle the remaining chocolate chips on top.
Bake for 15 minutes, until the tops of the muffins are set and a toothpick inserted into the center comes out clean. Remove from the oven. Allow the muffins to cool in the pan for ~10 minutes before removing.
Store them in an air-tight container for up to 5 days, or freeze them for up to 3 months.