• Heat the water, milk, and 2 tablespoons of the butter in a microwave on high power for a few seconds, until warm (110°F).
• Add the yeast, stir, and set aside for about 10 minutes.
• In a bowl, stir together the flour, baking powder, and salt. Set aside.
• Stir the maple syrup into the yeast mixture.
• Pour into a large bowl. Beating by hand or using an electric mixer on medium speed, add 1 cup of the flour mixture to the yeast mixture. Continue, adding the flour mixture, 1 cup at a time, until all the flour is incorporated.
• If working by hand, turn the dough out onto a floured surface and knead for about a minute. If using a mixer, switch to the dough hook and mix until the dough forms a ball. The dough will be a little sticky.
• Pat a little oil all over the ball of dough and place back in the bowl. Cover the bowl with a clean towel and place in a warm place to rise for 1 hour.
• Butter an 8-inch square baking pan.
• Mix the cinnamon and sugar together and set aside.
• Turn out the dough onto a lightly floured surface and roll out to a 10 x 16-inch rectangle.
• Melt the remaining 2 tablespoons of butter. Brush 1 tablespoon of the butter all over the surface.
• Sprinkle with the cinnamon-sugar. Sprinkle with the chocolate chips.
• Starting at the short end, roll up the dough.
• Cut into nine slices 1½ to 2 inches wide.
• Place the rolls in three rows of three, seam side down, in the prepared pan. Brush with the remaining tablespoon of melted butter.
• Cover with a clean towel and set in a warm place to rise for 30 minutes. While the rolls rise, preheat the oven to 350°F.
• Uncover the pan and bake for 25 to 30 minutes. Let cool.

To make the topping:

• Microwave the milk and chocolate chips together on medium power for 15 seconds.
• Stir and keep heating at 5-second increments until completely melted. Chocolate will burn in the microwave if you don’t watch it carefully.
• When melted, stir in the vanilla. Drizzle, back and forth, all over the top of the baked rolls. These are ready to eat anytime.