Line an 8 x 8-inch pan with parchment paper and set aside.
In a microwave safe bowl or stovetop, melt the peanut butter with syrup until combined. Add the oats and mix well, until fully incorporated.
Transfer the mixture into the lined pan and press into it firmly. Refrigerate for at least 30 minutes, to firm up, before slicing into bars.
* Can use smooth almond butter, cashew butter, sunflower seed butter, or tahini instead.** Can use agave nectar or honey (not strictly vegan) instead. TO STORE: Place leftover bars in a sealable container and keep them in the fridge at all times. They will remain fresh for at least 2 weeks.TO FREEZE: Chill your bars and then freeze them, by placing them in a ziplock bag. They will keep well frozen for up to 6 months.