Add warm water to the bowl of your mixer and stir in the yeast & sugar. Let sit 5 minutes, until frothy.
Add the oil & 1 egg to the bowl. Add the flour and salt, mixing on medium-low speed with the hook until the dough holds together, about 2 minutes. The dough should clean the sides of the bowl. If not, add additional flour by the tablespoon.
Increase speed to medium and knead the dough for 5 minutes. Then transfer the dough to a large bowl that has been lightly greased with oil. Cover the bowl with a damp towel and let rise in a warm place until doubled in bulk, 1 to 1½ hours.
Line a baking sheet with parchment. Turn out the dough onto a lightly floured surface. Divide the dough in half and then each half into 8 pieces. A kitchen scale makes this easy: 1.8oz for each slider bun.
Roll into rounds and flatten with the palm of your hand onto the baking sheet; placing buns about ½ to 1 inch apart). Cover with a damp towel and let them rise for 20 minutes + oven preheating time. Preheat oven to 350˚F.
Mix all the ingredients for the Everything topping in a small bowl. Whisk the remaining egg with 1 Tbsp water. Brush the buns with the egg wash and sprinkle all of the Everything topping over the buns.
Bake for 18-22 minutes, or until golden brown. Let cool at least 10 minutes before slicing and serving. Store leftovers in a zip-top bag at room temperature.