Line a 12-count standard muffin tin with cupcake liners. Preheat the oven to 375°F.

In a large bowl, beat together the eggs, granulated sugar, and fine salt with an electric mixer on high speed for 4-5 minutes. The eggs should be light in color.

Add sour cream, vegetable oil, and vanilla extract. Beat on low speed until just combined, about 30 seconds.

In a medium bowl, combine and whisk the dry ingredients: all-purpose flour, baking powder, and baking soda. Add the flour mixture to the wet ingredients ⅓ at a time, mixing on low speed just until combined. DO NOT OVERMIX.

In a small bowl, toss the blueberries with all-purpose flour to coat. Gently fold the blueberries into the muffin batter.

Spoon the muffin batter equally into the muffin pan filling each cup ¾ to the top. Bake at 375°F for 25-30 minutes, or until the tops are golden and a toothpick inserted into the center comes out clean. If using frozen berries, increase baking time to 30-35 minutes.

Let the baked muffins cool in the muffin pan for 5 minutes before transferring to a cooling rack until room temperature.