Heat the vegetable oil in a skillet over medium heat. Add the finely diced yellow onion and sauté until soft and translucent, about 5 minutes.

In a bowl, whisk together the large eggs, sea salt, black pepper, onion powder, and dried parsley. Pour this mixture over the sautéed onions, scrambling until the eggs are fully cooked through, roughly 3-4 minutes.

Stir in the crispy crumbled bacon and shredded sharp cheddar cheese. Mix gently until everything is well combined.

Preheat your air fryer or oven according to the manufacturer's instructions.

Unroll the refrigerated biscuit dough and roll it out slightly on a floured surface. Cut the dough into circles to create pockets for the filling.

Place a generous spoonful of the filling in the center of each dough circle. Fold the dough over and crimp the edges with a fork or your fingers to seal them tight.

Melt the unsalted butter and brush it over the tops of the hand pies. Spray with nonstick spray or lightly oil them.

Cook in the air fryer or on a baking sheet until they are golden brown and flaky, about 12-15 minutes.