Place three and a half cups of all purpose flour, three tablespoons of unsweetened cocoa powder, six tablespoons of granulated sugar, and one packet of instant yeast in the standing mixer (or electric mixer) and mix until combined.
Stir in one teaspoon of salt.
Switch out the attachment on the stand mixer. Use the dough hook and add the one cup of warm water, a quarter cup of whole milk, and the half stick of cubed room temperature unsalted butter.
Mix on low speed until dough comes together. It should take about to 2-3 minutes.
Continue mixing for another 7 minutes, until dough is soft and elastic and pulls away from the sides of the bowl.
Break the Divine - 55% Semi-Sweet Baking Chocolate Bar into square chunks.
Add Divine - 55% Semi-Sweet Baking Chocolate Bar and keep kneading for a few more seconds until combined.
Place dough in a large bowl brushed with butter, and toss to coat.
Cover with plastic wrap and put the dough in a proving drawer and let rise 1 hour and 45 minutes, or until doubled in size.
When the dough has risen, gently push it down to remove air.
Divide the dough into 20 equal portions and shape each one into a smooth ball.
Arrange on two baking sheets lined with parchment paper, keeping as much space between them as possible.
Cover and place them in the proving drawer for 50 minutes or until again doubled in size.
Preheat oven to 350F.
Bake the chocolate buns for 20 minutes.
Transfer the chocolate buns to a wire rack to cool.
Serve warm or at room temperature.