Sourdough Discard Hamburger Buns

Combine the warm water, instant yeast, and sugar in the bowl of a stand mixer or large mixing bowl*. Add the flour, sourdough discard, beaten egg and salt. With the mixer on low, slowly pour in melted butter. Increase speed to medium and mix until a shaggy dough forms, about 2 minutes.
Transfer the dough to a work surface and knead until a smooth dough forms, about 3-4 minutes. The dough should be smooth and soft, but not sticky. If needed, add more flour or water (1 Tablespoon at a time) to reach your desired consistency.
Transfer the dough to a large oiled bowl and cover with plastic wrap. Let rise for about 90 minutes, or until doubled in size. Prepare two baking sheets lined with parchment paper.
Turn the dough onto a work surface and divide into 8 equal-sized pieces. This doesn't have to be exact, but if you do want perfectly identical buns, weigh the dough and divide that number by 8 to determine how much the dough for each bun should weigh (for me, this was about 103g each).
Using one palm for friction, roll each piece of dough into a smooth ball. Place the buns seam-side down on the prepared baking sheets. Gently press to flatten each bun until about 3 inches in diameter. Cover the buns with plastic wrap and let rise for 60 minutes until puffed.
At the end of the rise, preheat the oven to 375℉. Lightly brush the buns with egg wash, then sprinkle with sesame seeds or desired toppings. Bake for 20-22 minutes until golden brown. Let cool, then slice and serve.