Begin by chopping the semi-sweet chocolate and placing it in a medium saucepan over low heat. Stir gently until it's fully melted and smooth, which should take about 5 minutes. Remove it from heat and let the chocolate cool for about 5-10 minutes while you prepare other ingredients.

In a large mixing bowl, sift together 1 cup of all-purpose flour, ½ cup of Dutch process cocoa powder, ½ teaspoon of baking powder, and ½ teaspoon of salt.

In a stand mixer bowl, combine ½ cup of unsalted butter, ½ cup of brown sugar, and ¼ cup of granulated sugar. Beat these together at medium speed for about 2 minutes until the mixture is light and fluffy. Gradually add the cooled melted chocolate and 1 teaspoon of pure vanilla extract, mixing for another 2 minutes until fully incorporated.

Add in 1 large egg and 1 egg yolk to the wet mixture, blending at medium-high speed for about 2 minutes.

Slowly add the dry ingredient mixture into the chocolate batter, mixing until just combined. Fold in ½ cup of chocolate chips, 1 cup of crushed Oreo pieces, and ¼ cup of Oreo crumbs.

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

Using a heaping 2-tablespoon cookie scoop, place six dough balls on a lined baking sheet, keeping them spaced apart. Bake the cookies for 13-15 minutes, ensuring they set while still looking soft in the middle.

Remove the baking sheet from the oven and let the cookies cool on the sheet for about 5 minutes before transferring them to a wire rack.