Begin by breaking the semi-sweet chocolate into small pieces and placing them in a saucepan. Melt over low heat, stirring gently for about 5-7 minutes until smooth and glossy. Once melted, remove it from the heat and let the chocolate cool slightly to avoid cooking the eggs later.

While the chocolate cools, take a few Oreos and blend them into fine crumbs using a food processor or a plastic bag and a rolling pin. Then chop additional Oreos into medium-sized pieces with a knife. Set aside.

In a mixing bowl, sift together the all-purpose flour, Dutch process cocoa powder, baking powder, and salt. This combines and aerates the flour. Set aside.

In a large mixing bowl, add room temperature unsalted butter, brown sugar, and white granulated sugar. Beat on medium speed for about 2 minutes until light and fluffy. Add the slightly cooled melted chocolate and pure vanilla extract, mixing until well combined.

Crack in the large eggs and beat the mixture on medium speed until fluffy and well combined. This is essential for texture.

Gradually add the dry ingredient mixture to the wet ingredients, mixing on low speed until just combined to maintain texture. A thick, dark batter should form.

Gently fold in the chocolate chips, Oreo crumbs, and chopped pieces using a spatula for even distribution.

Cover the mixing bowl with plastic wrap and chill the dough in the refrigerator for about 30 minutes while preheating your oven to 350°F (175°C).

Line baking sheets with parchment paper and use a cookie scoop to drop rounded tablespoons of dough onto the sheets. Bake for 13-15 minutes, or until edges are set but centers are slightly soft.

Let the cookies sit on the baking sheet for 5 minutes before transferring to a cooling rack.