Mix yogurt, milk, egg, butter, syrup, and vanilla in a blender until smooth. Add flour, baking soda, and salt. Process to combine. If making batter ahead, refrigerate up to 2 days.
Coat a skillet with cooking spray; heat over medium. Add batter, using about ¼ cup per pancake. Scatter 1 Tbs. blueberries over each. When browned, flip and cook through, about 2 minutes per side. (Pancakes can be frozen up to 1 month; toast before serving.) Top with butter and syrup, and more berries.
Make all the pancakes on the weekend and cool. Freeze in a single layer on a baking sheet for 2 hours. Layer pancakes in an airtight container with parchment paper in between each row; freeze up to 1 month. To reheat, pop in the toaster.