In a large mixing bowl, combine the oat flour, vanilla protein powder, ground flaxseed, and salt. Stir until evenly mixed.
Add the sunflower seed butter, pure maple syrup, unsweetened almond milk, and vanilla extract to the dry ingredients.
Mix everything together thoroughly using a spatula or your hands until a thick, sticky dough forms.
Fold in the mini dairy-free chocolate chips evenly throughout the dough.
Line an 8×8 inch baking pan with parchment paper, leaving some overhang for easy removal.
Press the dough evenly into the prepared pan, smoothing the top with a spatula.
Place the pan in the refrigerator and chill for at least 1 hour to firm up.
After chilling, lift the dough out of the pan using the parchment overhang and cut into 12 equal bars.
Store the bars in an airtight container in the refrigerator for up to 1 week or freeze for longer storage.