Place the butter and agave (or honey) in a bowl or a standing mixer and beat for 1 minute.
Add the egg, vanilla and peanut butter and beat another minute on medium speed or until smooth.
In a separate bowl, combine all the dry ingredients and mix to combine.
Slowly add the dry ingredients to the wet and mix to incorporate.
Drop 1 tbsp of the cookie dough onto a Silpat or parchment-lined cookie sheet. Flatten down each ball of cookie dough with the back of your hand or with the back of a fork making a checkerboard pattern.
Bake for 10-12 minutes.
Cool and serve.
Notes
If you'd like to freeze these cookies to bake in the future follow the steps below:Freeze dough after step 6 for 30 minutes then place par-frozen cookies in a ziploc bag, label and freeze for up to 4 months. When ready, pop them on a silpat or parchment lined cookie sheet and bake adding an additional 1-2 minutes.