In a medium mixing bowl, whisk together the flour, baking powder, baking soda, and salt.
In a separate mixing bowl, whisk together the sourdough discard, soy milk, olive oil, egg, and sugar until smooth.
Pour the dry ingredients into the wet ingredients and mix until just combined. Do not overmix. A few lumps are fine.
Let the batter rest for at least 5 minutes.
Heat a nonstick pan over medium heat and lightly grease with avocado oil spray or butter.
Pour batter onto the pan (about 1/4 cup per pancake).
Cook until bubbles form on the surface and edges look set, about 2–3 minutes.
Flip and cook for another 1–2 minutes until golden.
Serve warm or let cool and freeze for later.