In a large bowl, combine the flour, buttermilk, starter, and sugar. Cover with plastic wrap, and let rest in the refrigerator for 4 hours or up to overnight.
2 cups (240 g) all-purpose flour, 1 ½ cups (340 ml) buttermilk, 1 cup (227 g) sourdough starter, 2 tablespoons granulated sugar
The next day, add the oil, eggs, salt, baking soda, and vanilla to the flour mixture. Stir well to combine.
½ cup (113 g) cooking oil, 2 (100 g) large eggs, 1 teaspoon salt, 1 teaspoon baking soda, 1 teaspoon vanilla extract
Preheat the waffle iron according to manufacturer’s instructions. Scoop about 1 cup of batter on the hot waffle iron, and cook for 3-4 minutes. Carefully remove the hot waffle to a waiting plate and continue with the remaining batter.
Serve immediately with maple syrup and fresh fruit. Store leftovers in the refrigerator for up to 3 days.