In a mixing bowl, add the 2/3 cup heavy cream, milk (1 cup milk + 1 Tbsp. milk), 1 1/2 tsp. salt and 1 Tbsp. active dry yeast and mix gently and let it rest for 10 minutes.
Proceeds to add 1 egg, 65 g sugar, 57 g cake flour, 480 g bread flour, 1 Tbsp. active dry yeast, and 1 1/2 tsp. salt (add it in that order). Mix the dough ingredients together with a wooden spoon until the dough comes together, and then knead it by hand using floured hands for 20 minutes.
After 20 minutes, the dough is ready for proofing. Cover the bowl with a damp towel and place in a warm spot for 60-90 minutes, until the dough doubles in size.
The Hot Dogs
In the meantime, heat 1 Tbsp. vegetable oil in a skillet over medium heat. Add the 6 hot dogs, and allow them to crisp slightly and get some color on them. Set aside on a plate to cool.
The Cooking
After the hour of proofing, put the dough back in the mixer and stir for another 5 minutes to get rid of air bubbles. Dump the dough on a lightly floured surface and cut into 6 equal pieces. Take each piece of dough and roll it into a 10-12 inch rope, keeping the middle thicker than the ends.
Preheat the oven to 350℉. Roll the rope around a hot dog, tucking in the ends. Place on a parchment-lined baking sheet (keep the buns 2-3 inches apart). Repeat until all the buns are assembled.
Cover the baking sheet with a kitchen towel and allow the buns to rise in a warm place for another hour. The buns should close to double in size. Brush with egg wash (1 tsp. water + 1 egg), sprinkle on top 1 Tbsp. roasted white sesame seeds and bake the buns for 25-30 minutes, until they have a shiny golden crust.
Remove from the oven and immediately brush the buns with sugar water (2 tsp. hot water + 1 tsp. sugar). This last step gives them that signature Chinese bakery shine.