Preheat the oven to 375. Spray a regular size muffin tin with non stick spray and set aside
Stir together the flour, baking soda and lemon zest in a medium bowl. Set aside
Combine the melted butter, applesauce, sugar and eggs in a large bowl. Stir in the sour cream. Stir in all but 1 Tbsp of the flour mixture. Mix until just combined and moistened – do not overmix
Place the blueberries in the bowl with the remaining 1 tablespoon of flour and toss to coat.
Fold the flour dusted blueberries into the batter.
Spoon the batter into the prepared muffin tins almost to the brim.
Bake until the muffins are golden brown and a toothpick inserted in the center comes out clean, 20 to 25 minutes. Cool the muffins in the tin for 5 minutes, then take them out (may need to run a thin knife around the edge) and let them cool on a rack, eat them warm!
