Preheat oven to 350F. Line two baking sheets with Silpat baking mats; set aside.

To a large bowl, add the butter, ½ cup sugar, and beat on high-speed with a handheld electric mixer to cream the batter.

Add the egg, vanilla, and beat to incorporate. Stop to scrape down the sides of the bowl.

Add 1 cup flour, salt, baking powder, baking soda, and beat to just incorporate; don't overmix.

Add the buttermilk and beat to incorporate; set aside.

To a separate small bowl, add 1 cup blueberries, 1 tablespoon flour, toss to combine, and add the blueberries and any residual flour to the large mixing bowl. Stir gently by hand to incorporate.

Using a large cookie or ice cream scoop, divide the dough in 10 equal portions, distributed equally on the two baking sheets. Flatten the dough mounds slightly so they're uniformly about 2 inches high and not mounded up in the center to ensure even baking.

Evenly distribute the remaining ½ cup blueberries over the 10 muffin tops, an extra 3-4 blueberries per muffin top.

Bake for about 20 minutes, or until muffin tops are set in the center and cooked through, the bottoms will be ever so slightly golden browned around the edges; they firm up as they cool. Start watching at 15 minutes since all ovens and ingredients vary. Don't overbake to ensure soft and tender muffin tops. BAKING TIPS - Midway through baking I recommend turning your baking sheets for even baking and browning. If your berries are not very sweet or if you prefer slightly sweeter muffin tops, I recommend adding a pinch of sugar to each muffin top when you go to turn your baking sheets midway through baking.

Allow the muffins tops to cool on the baking sheets for about 10 minutes before moving them. Muffin tops are best fresh but will keep airtight for up to 5 days.