In a large bowl, combine the rolled oats, ground flaxseed, and pumpkin spice blend.
Add the pumpkin purée, almond butter, maple syrup, and vanilla extract. Stir until well combined.
If using, fold in the chopped pecans and mini vegan chocolate chips.
Roll the mixture into small balls (about 1 inch in diameter).
Place the energy balls on a baking sheet and refrigerate for at least 30 minutes to set.
Store in an airtight container in the fridge for up to a week.