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

If using rolled oats, grind them in a blender or food processor until they reach a fine, flour-like texture and measure out 1 cup (plus 2 tablespoons if using rolled oats).

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

In a separate bowl, stir together the oat flour, baking powder, and dried parsley (if using) until well mixed.

Add the dry ingredients to the wet ingredients gradually, stirring with a spatula or spoon until a soft dough forms that holds together without crumbling.

If the dough is too sticky, add 1 to 2 tablespoons more oat flour, a little at a time, until it is workable; if it is too dry, add 1 teaspoon more yogurt and mix again.

Shape the dough into a disk with your hands, then lightly dust a clean work surface with oat flour.

Place the dough on the floured surface and roll it out to 1/4 inch thickness, adding a light dusting of oat flour as needed to prevent sticking.

Use a 1- to 2-inch heart-shaped cookie cutter to cut out biscuits, gathering and re-rolling the dough scraps until all the dough is used.

Arrange the heart biscuits on the prepared baking sheet, leaving a small space between each biscuit.

Bake for 18 to 20 minutes, or until the biscuits are set and the edges are just turning a light golden color.

Remove the baking sheet from the oven and allow the biscuits to cool completely on a wire rack before serving to your dog.