Preheat your oven to 350°F (175°C).
First, make a chia "egg": Combine 2 tablespoons of chia seeds with 4 tablespoons of water, mix thoroughly, and place in the fridge for 5 minutes to gel.
In a mixing bowl, add 1 cup of peanut butter (or almond butter for a paleo option), 1/4 cup of almond flour, 1/3 cup of coconut sugar, 1/2 teaspoon of baking soda, and the prepared chia "egg". Mix all ingredients well until combined.
Roll the dough into balls and place them on a baking sheet. Press each ball down slightly, then use your thumb to press down in the center, creating a small well in the middle of each cookie.
Bake for 12 minutes.
While the cookies are baking, prepare the cherry jam: Put 1 cup of frozen cherries in a small saucepan over medium heat. Cook for 3-4 minutes until you can easily mash them down with the back of a spatula. Mash the cherries, then turn off the heat and blend in 1 tablespoon of maple syrup and 1 teaspoon of chia seeds. Allow the jam to cool until it thickens.
Once the cookies are done baking, if the center of any cookie has risen, use a small spoon to gently press it back down while the cookie is still hot.
Use the same small spoon to spoon your cooled cherry jam into the center of each cookie.
Enjoy your PB & J cookies, perhaps with a glass of plant-based milk!