In a large bowl of your stand mixer or manually in a large mixing bowl, whisk together the warm milk, yeast, and 1 Tablespoon of sugar together. Cover with a plastic wrap or towel and allow to sit until the yeast is activated and looks foamy, about 5-10 minutes.

Add the egg, butter, salt, rest of the sugar, and half of the flour. Using a dough hook or paddle attachment, beat the mixture on low speed for 30-45 seconds, scraping down the sides of the bowl with a rubber spatula in between, then add the other half of the flour.

Transfer the dough to a lightly greased bowl and cover with a clean towel or cling wrap. Let it rest in a warm spot for 1 hour, or until the dough has doubled.

While the dough is resting, add butter into a saucepan over medium-low heat. Once melted, turn off the heat and add in the flour, breadcrumbs, milk, sugar, and cinnamon together. Mix until combined.

When the dough has doubled, punch down the dough with your clean fists to release the air inside. Then divide the dough into 14-16 equal pieces (it does not need to be exact), then shape each one into a smooth ball. Transfer the dough pieces onto a floured surface. Then, roll each dough into a triangle shape.

Spread the sugar filling on each piece of the dough. Starting from the long edge of the triangle, roll each piece inwards. Brush on the extra melted butter, then roll in the crushed bread crumbs.