Preheat the oven to 400 degrees F and line a 12-cup muffin pan with paper liners.
Combine the yogurt, melted butter, eggs, lemon zest, lemon juice, and vanilla in a bowl or large measuring cup and whisk until smooth.
Pour the wet ingredients over the cake mix and stir until almost completely incorporated, but the dry mix is still streaking the batter.
Gently fold in the blueberries until just mixed and no dry ingredients are showing. The batter will be very thick.
Divide the batter among the 12 muffin cups. It will look like too much batter but that’s ok, the batter will fill the cups and rise into big bakery-style muffins.
Bake the blueberry muffins at 400 degrees F for 18-22 minutes until lightly browned around the edges and a toothpick inserted comes out clean.