Mix the flour, sugar, salt and baking powder together in a bowl.
In a separate large bowl, mix the 3 eggs, oil, vanilla, cinnamon, and orange zest, if using.
Then in two batches, mix all the dry ingredients into the wet ingredients. Work the dough to form a loose dough. Then refrigerate dough for at least 30 minutes.
Take off a small piece of dough and roll into a rope. Cut 12 slots and then cut into a strip. Form a circle and pinch together. Repeat with remaining dough, keeping in fridge until ready to roll. The dough may come apart when rolling- just push it together. It’s forgiving. You may find the dough oil-y and that’s okay. It bakes up and does not taste or feel greasy. Trust me!
Place on a parchment lined baking tray. Mix 1 egg with a fork for egg wash. Brush cookies with egg wash and then sprinkles of choice.
Bake at 350 F for 18 minutes. Put the tray in the middle rack of the oven for even browning.