In the bowl of a stand mixer, combine yeast, warm water, and 1 tablespoon of the sugar. Let the mixture stand for 5 minutes or until foamy.
Add the milk, butter, eggs, the remaining sugar, salt, and cocoa powder. Stir everything to combine.
Using the dough hook, add 2 and 1/4 cups of flour and mix on low speed until the dry ingredients are moistened. Increase the speed and continue to mix until the ingredients are fully incorporated.
With the mixer running, add 2 cups of flour gradually. Keep mixing, occasionally scraping the bottom and sides of the mixer bowl, until the dough starts to gather in the center of the bowl.
If the dough is still too wet and sticky, add the remaining 1/2 cup of flour and keep mixing until the dough has lost a lot of stickiness.
Lightly grease a clean working surface and your hands with cooking oil. Turn the dough over on the working surface ad knead until it is smooth and elastic.
Place the kneaded dough in a lightly oiled bowl and cover with a plastic film or a clean towel. Let rise for about 1 1/2 to 2 hours or until doubled in size.
When the dough has doubled in size, gently deflate and turn out on a work surface. Form into a log and divide into 20 pieces.
Take one portion, roll into a ball and then flatten. Spoon about a tablespoon of Nutella in the center and fold the edges of the dough around the center to cover the filling.
In a shallow plate, combine breadcrumbs and graham cracker crumbs.
Shape it into a smooth ball and press the ends underneath to seal. Roll the dough in the bread and graham crumbs mixture. Repeat with the rest of the dough portions.
Arrange the assembled chocolate pandesal on a parchment-lined baking pan and cover loosely with a clean kitchen towel. Let rise for another hour or until puffy.
Bake in a preheated 350 F for about 18 to 20 minutes. The tops should feel firm to touch with a bit of bounce.