In a large bowl, dissolve yeast and a pinch of sugar in warm milk, then let it sit for 5-10 minutes until foamy. Whisk in the remaining granulated sugar, melted butter, salt, and egg.

Gradually add the flour, mixing until a shaggy dough forms, then turn it out onto a lightly floured surface. Knead for 5-7 minutes until the dough is smooth and elastic.

Place the dough in a lightly oiled bowl, cover with plastic wrap, and let it rise in a warm place for 60-90 minutes, or until doubled in size.

Punch down the risen dough and roll it into a 12x18-inch rectangle on a lightly floured surface. In a small bowl, mix softened butter, brown sugar, cocoa powder, cinnamon, and chocolate cookie crumbs to create the filling.

Spread the filling evenly over the dough, leaving a small border on one long edge. Tightly roll up the dough from the opposite long edge and pinch the seam to seal it.

Slice the log into 10-12 equal pieces and arrange them in a greased 9x13-inch baking dish.

Cover the baking dish and let the rolls rise again in a warm place for 30-45 minutes, or until puffy. Preheat your oven to 375°F (190°C) during this time.

Bake for 20-25 minutes, or until golden brown and cooked through. If rolls are browning too quickly, you can loosely tent them with foil.

While the rolls are cooling slightly, whisk together powdered sugar, milk, and vanilla extract until smooth to make the glaze. Add more milk if a thinner consistency is desired.

Drizzle the glaze generously over the warm cinnamon rolls before serving. Enjoy warm.