Add the milk and yeast to the bowl of a stand mixer fitted with the dough hook attachment. Allow it to sit for 5 minutes, or until it is foamy on top. 

Next, add the eggs, pumpkin puree, and vanilla extract. Whisk to combine. 

In a small bowl, whisk together the flour and granulated sugar. 

With the mixer on low, slowly add the dry ingredients to the wet ingredients. 

Once all of the flour has been incorporated, continue mixing for 1-2 minutes, or until the dough starts to form into a ball. 

With the mixer on low, add the butter 1 tablespoon at a time, allowing each piece to incorporate fully before adding the next one. 

Once all of the butter has been added, knead the dough for 1-2 minutes or until a smooth ball forms. 

Transfer the dough to a lightly oiled bowl and place it in the fridge overnight (at least 12 hours). 

Once the dough has rested, remove it from the fridge and allow it to come to room temperature-- about 1 hour. Then, continue with the filling below. 

Heat the cream in a small saucepan until it starts to steam. Remove from the heat and add the chopped chocolate and stir until the chocolate is fully melted. Set aside to cool for 5 minutes. 

In a small bowl, stir together the chocolate mixture and softened butter. 

Add the powdered sugar, cocoa powder, and cinnamon. Mix to combine. 

Grease a 9x5” loaf pan with butter or nonstick baking spray and set it aside until ready to use. 

Roll the dough out onto a lightly floured surface until it is ¼” thick. It should be about 15x12”. 

Spread the filling over the dough, making sure to go all the way to the sides. 

Roll the babka tightly into a log. Cut the log in half lengthwise and place it cut side up on the board. 

Twist strips together and smush the dough into your loaf pan. 

Set the dough in a warm place to rise for 1 hour. 

While the dough rises, preheat your oven to 375F. 

Bake the babka for 40-45 minutes, or until it is golden brown on top and set on the center. 

Before the babka comes out of the oven, make the syrup by combining the sugar and water in a small saucepan over medium heat. Cook for 5 minutes, or until the sugar is dissolved. 

When the babka finishes baking, remove it from the oven and brush the top with the glaze. 

Allow the babka to cool in the pan for 5 minutes, then remove it to a wire rack to cool completely. 

Slice and enjoy. Store in an airtight container in the fridge for up to two days.