Melt butter and set aside to let it cool.
In a large mixing bowl, whisk together flour, sugar, baking powder, baking soda, and salt. Set aside.
In a separate bowl, whisk together sourdough discard, milk, eggs, and vanilla extract until well-combined.
While whisking, drizzle in melted butter (it’s OK if the butter forms small clumps).
Add the wet ingredients to the flour mixture and use a spatula or wooden spoon to gently fold together the batter until just combined. All the flour should be absorbed, if you notice small lumps or small bits of butter in the batter that is fine, don’t over-mix or your pancakes could be rubbery and dense.
Set the pancake batter aside and brush a skillet with olive oil or melted butter. Turn the stovetop heat to medium and let it the pan warm until you can feel the heat radiating from it if you hover your hand several inches above the pan. It is also good to let your pancake batter to rest while the pan warms, this will thicken it slightly and help make for thicker pancakes.
Portion pancake batter into center of the pan (I use ½-⅔ cup of batter per pancake) and cook until bubbles in the batter burst and the edges begin to appear cooked.
Use a spatula to carefully flip the pancake and continue to cook until pancake is golden brown.
Remove to a plate and repeat with the remaining pancakes.
Serve immediately, we like to add butter, maple syrup, fruit or even whipped cream to our pancakes!