Combine the flour and milk in a small saucepan over low heat. Cook, whisking constantly, until the mixture thickens to a paste, 2-3 minutes.

Transfer the paste into a small bowl and let cool for 5-10 minutes.

Stir the yeast, pinch of sugar, and warm milk together in small bowl. Let rest until the top of the mixture is foamy, 5-10 minutes.

In the bowl of a mixer fitted with a dough hook, combine the sugar, flour, salt, and egg. Add the tangzhong and yeast mixture mix on low speed until a shaggy dough forms.

Add the butter, one piece at time, mixing until each piece is fully incorporated before adding the next.

Increase the speed to medium-high and beat until the soft, smooth, and slightly sticky, about 8-9 minutes.

Use damp hands to shape the dough into a smooth ball, pinching and pulling the ends together.

Place the dough ball into a large, greased mixing bowl. Cover with plastic wrap and set in a warm place to rise until the dough has doubled in size, about 2 hours.

Line two baking sheets with parchment paper. Set aside.

Punch the dough down in the bowl, then transfer to a lightly floured workspace. Roll the dough out to ¼ - ½ inch thickness. Use a large Mickey Mouse cookie cutter to cut out the shapes.

Place the cut out dough shapes onto the parchment lined baking sheets, about 2 inches apart. Firmly press 3-4 pieces of hot dog into the ears and face portion of the dough.

Cover the buns with plastic wrap and let rest in a warm place until doubled in size, about 1 hour.

Preheat the oven to 350 F. Whisk together the egg and heavy cream to make the egg wash.

Brush each bun with egg wash and sprinkle with green onion and sesame seeds.

Bake for 18-20 minutes or until the buns are golden brown. Serve warm or cool completely.