Line a small baking sheet or plate with parchment and set aside. In a microwave-safe bowl combine the peanut butter and honey; microwave in 15–20 second bursts, stirring between bursts, just until the mixture loosens and becomes easy to stir (about 30–40 seconds total).
Stir the vanilla extract and sea salt into the warmed peanut butter mixture. This helps the flavors meld and makes the dough more pliable for shaping.
In a separate large bowl whisk together the oats, protein powder, ground flaxseed and cinnamon so they’re evenly blended and there are no clumps of protein powder.
Pour the peanut butter-honey mixture over the dry mix and fold with a sturdy spatula or wooden spoon until a thick, slightly sticky dough forms. If the mixture feels too dry, add 1 teaspoon warm water at a time (up to 2 tsp) until it holds together.
Fold in the mini chocolate chips by hand so they are evenly distributed without melting. Press the mixture together a few times to test consistency; it should hold when squeezed.
Using a tablespoon or small cookie scoop, portion the dough and roll into 1-inch balls between your palms. Place the formed balls on the prepared sheet about 1/2 inch apart. This recipe should make roughly 16 balls.
Chill the tray in the refrigerator for at least 20–30 minutes to firm up the balls — this helps them keep shape. For firmer, grab-and-go bites, freeze for 10 minutes longer.
Once firm, transfer the peanut butter protein balls to an airtight container. Store in the refrigerator for up to 10 days or freeze for up to 3 months; thaw in the fridge before eating.