Whisk Dry Ingredients: In a large mixing bowl, whisk together unbleached all-purpose flour, sugar, baking powder, baking soda, and fine sea salt until evenly distributed.
Whisk Wet Ingredients: In a separate medium bowl or large measuring cup, whisk together room-temperature cultured buttermilk, eggs, melted butter, and pure vanilla extract until completely blended.
Gentle Fold (The Golden Diner Rule): Pour wet ingredients into the dry bowl. Using a silicone spatula, gently fold just until incorporated. Do NOT overmix! The batter should remain thick and lumpy with visible flour pockets.
Rest the Batter (Crucial): Let the pancake batter rest undisturbed on the counter for 10 full minutes. The buttermilk acid activates the baking soda and powder, creating tiny air bubbles that guarantee lofty diner thickness.
Preheat & Butter Griddle: Heat a heavy cast-iron skillet or nonstick griddle over medium heat (around 325-350°F / 165-175°C). Lightly grease with a pat of butter or brush of avocado oil.
Pour & Dot with Berries: Ladle 1/3 cup of batter per pancake onto the hot griddle. Immediately press 8-10 fresh blueberries directly into the top of the wet batter (this prevents burning and burst discoloration).
Griddle & Flip: Cook for 2 1/2 to 3 minutes until bubbles form on the surface, edges begin to look matte, and the underside is deeply golden. Gently flip and cook the second side for another 1 1/2 to 2 minutes until cooked through and springy.
Stack & Serve: Stack tall on warm plates, top with a generous dollop of whipped sweet cream butter, fresh blueberries, and warm pure maple syrup.