Heat a skillet or griddle over medium-low heat. (Cast iron or enameled cast iron works best.)
In a large mixing bowl, whisk together 56 g melted butter, 60 g sour cream, 2 eggs, 500 g sourdough discard, 6 g vanilla extract, and 50 g sugar until smooth.
In a separate bowl, whisk together 100 g all-purpose flour, 1 tsp cinnamon, 1/2 tsp salt, 2 tsp baking soda, and 2 tsp baking powder. Fold into the wet batter just until combined. Small clumps of flour are good—do not overmix!
Add ~50 g sparkling water(or milk) and gently mix until incorporated. The batter should slowly fall off a spoon. Adjust liquid as needed depending on your discard's consistency.
Add 1/2 tbsp butter to the preheated skillet. Using a lightly oiled 1/4 cup measuring cup, scoop batter onto skillet, cooking 3-4 pancakes per batch.
Flip when the bottom has set and the top is covered in bubbles (about 3-4 minutes). Cook the other side until golden brown, about 1 minute more.
Repeat with remaining batter, adding butter to the skillet as needed. Serve warm with your favorite toppings.
Notes
Freezing tip: Freeze cooked pancakes in a single layer on a parchment-lined baking sheet, then transfer to a freezer-safe bag for storage. Reheat straight from frozen in a toaster or skillet.
Flavor variations: Add chocolate chips, blueberries, or other mix-ins to the batter just before cooking.
Freshness matters: For the best flavor, use discard that’s less than 10 days old. Older discard can develop bitter or off flavors.
Adjust the heat: If your pancakes are browning too quickly or not cooking through, adjust the skillet temperature as needed. Medium-low heat works best for even cooking.
Batch cooking: Keep cooked pancakes warm by placing them in a 200°F (93°C) oven until ready to serve.