Unwrap the cream eggs and freeze them for at least 2–3 hours or overnight until solid.

In a medium bowl, whisk together the gluten-free flour, cornstarch, baking soda, and salt. Set aside.

In the bowl of a stand mixer fitted with the paddle attachment, cream the butter, brown sugar, and granulated sugar together until light and fluffy.

Add the eggs one at a time, mixing well after each addition, then mix in the egg yolks and vanilla extract.

Add the dry ingredients to the butter mixture and mix until just combined.

Fold in the chocolate chips or chopped chocolate.

Cover and refrigerate the dough for 45 minutes to 1 hour, until it is firm enough to shape.

Preheat the oven to 425°F (220°C) and line a baking sheet with parchment paper.

Portion the dough into 12–14 balls. Flatten each one in your hand, place a frozen cream egg in the center, and wrap the dough around it to seal.

Bake for 9–12 minutes until golden around the edges but still soft in the center.

While the cookies are still warm, use a large round cookie cutter or pastry ring to gently swirl around each cookie to shape it into a perfect circle. Let the cookies rest on the baking sheet for 5–10 minutes, then transfer to a wire rack to cool completely.