Preheat the oven to 375F (190C). Line a 12-cavity muffin tin with muffin papers.
In a medium bowl, whisk together the 2 cups flour, baking powder, baking soda and salt.
In a separate large bowl, beat together the butter and sugar until fluffy.
Beat in the eggs and vanilla extract until evenly combined.
Whisk in the sour cream until smooth.
Stir in about ½ of the flour mixture.
Whisk in the milk. Then stir in the rest of the flour mixture. A few lumps is ok, and expected. Do not overmix the batter.
Toss the blueberries in the 1 teaspoon of flour.
Gently fold the blueberries and chocolate chips into the batter.
Spoon the batter evenly between the 12 muffin papers. Each should be filled to the top.
Bake in the preheated oven for about 16-20 minutes, or until an inserted toothpick comes out clean. The tops should be golden when they're done baking.