Combine flour, ground oats, sugar, and salt in a medium bowl. Using a cheese grater, grate the cold butter directly into the flour mixture. Using a pastry cutter, cut in the butter until you have small and flaky pieces of dough. Sprinkle with water, a tablespoon at a time. Using your hands, start to combine and shape together until just barely combined. Do not knead or work together thoroughly. You are looking for a shaggy dough.

Once dough is mostly sticking together, turn it onto a floured surface and shape into a flat disc shape. Cover with plastic wrap and place in the freezer for about 15 minutes.

While the dough is in the freezer, you can work on dicing the strawberries into small pieces. Place them in a bowl and sprinkle with sugar. Mix together and place in the fridge.

Remove dough from freezer, unwrap, and place on a floured surface. Roll the dough out to a 1/8-inch thickness.

Preheat oven to 350 degrees F.

Using a heart-shaped cookie cutter (or any basic shape you'd like), cut out pieces of dough. Place half of them on a baking sheet lined with parchment paper or a silicone pad. Spoon a small amount of strawberries and a few chocolate chips in the center of the heart.

Brush the edges of the heart with all small amount of the beaten egg. Top with a second heart, pressing the edges down with the back of a fork to seal it all in. Brush tops with a thin layer of remaining egg whites and sprinkle with a tiny bit of sugar.

Place in the oven for 25 minutes or until the crust begins to brown. Remove from oven, let cool slightly and serve warm.