Preheat the oven to 350°F and line a baking sheet with parchment paper.

In a medium bowl, whisk together the egg, Greek yogurt, mashed strawberries, applesauce, and melted coconut oil until smooth.

In a separate bowl, stir together the oat flour, baking powder, and dried parsley if using.

Add the dry ingredients to the wet ingredients and stir until a soft, slightly sticky dough forms. If the dough is too wet to hold its shape, sprinkle in up to 1 tablespoon more oat flour and mix again.

Lightly dust a work surface or a sheet of parchment with oat flour, then turn the dough out and pat it to about 1/4 inch thick.

Use a small heart shaped cookie cutter to cut out biscuits and place them on the prepared baking sheet, leaving a little space between each one. Gather and reroll the scraps until all the dough is used.

Bake for 18 to 22 minutes, until the tops look dry and the edges are just starting to turn golden.

For crunchier biscuits, turn off the oven, crack the door, and let the biscuits sit inside for an additional 10 to 15 minutes.

Transfer the biscuits to a wire rack and let them cool completely before serving to your dog.