Combine warm water, 1 teaspoon of granulated sugar, and yeast in a small bowl, then stir gently and let it sit for 5-10 minutes until foamy.

In a large bowl, combine the foamy yeast mixture with warm milk, ½ cup melted butter, the egg, and the remaining ¼ cup granulated sugar. Gradually add 3 cups of flour and salt, mixing until a shaggy dough forms.

Turn the dough onto a lightly floured surface and knead for 5-7 minutes, adding up to another ½ cup of flour as needed, until smooth and elastic.

Place the dough in a lightly oiled bowl, turn once to coat, cover with plastic wrap, and let rise in a warm spot for 1-1 ½ hours until doubled in size.

In a medium bowl, combine ½ cup granulated sugar, 1 tablespoon cinnamon, and 2 tablespoons cocoa powder for the coating.

Punch down the risen dough, pinch off small pieces, roll into balls, then dip each into ⅓ cup melted butter before rolling in the cocoa-cinnamon-sugar mixture.

Layer the coated dough balls into a greased Bundt pan, sprinkling half of the chocolate chips between layers and topping with the rest after adding all dough balls.

Cover the Bundt pan with plastic wrap or a clean towel and let rise for another 30-45 minutes until noticeably puffy.

Preheat oven to 350°F (175°C), then melt ½ cup brown sugar with ¼ cup melted butter in a small saucepan and pour this sauce evenly over the risen dough.

Bake for 30-35 minutes until golden brown and cooked through, tenting with foil if browning too quickly.

Cool in the pan for 10-15 minutes, then carefully invert onto a serving platter and serve warm.