Gather all your ingredients: biscuit cookies, cacao powder, unsalted butter, condensed milk, dulce de leche, and pecans.

Roughly chop the biscuit cookies in a blender or food processor and blend with the cacao powder until coarse crumbs.

Transfer the mixture to a mixing bowl and combine with softened butter, dulce de leche, and condensed milk until smooth.

Fold in the chopped pecans evenly into the chocolate batter for added flavor and texture.

Scoop about a cup of the mixture onto plastic wrap, shape it into a tight log, about 2 inches in diameter.

Wrap the log tightly, refrigerate for at least 4 hours, or freeze for 1-2 hours for a firmer texture.

Unwrap the log once set, dust with powdered sugar if desired, and slice into thick pieces for serving.