Heat a large nonstick skillet or griddle over medium-low heat for about 5 minutes. You want it hot enough that water sizzles and dances when flicked on the surface, but not so hot that the butter burns instantly. Lightly grease with butter or a thin layer of oil.

In a large bowl, whisk together the flour, sugar, baking powder, baking soda, and salt until well combined. This ensures the leaveners are evenly distributed so you do not get a salty bite or a flat pancake.

In a medium bowl, whisk the buttermilk, egg, melted butter, and vanilla until smooth. The buttermilk and egg should be room temperature so the butter does not seize up into little clumps.

Pour the wet ingredients into the dry ingredients and stir with a rubber spatula until just combined. The batter should look lumpy with a few streaks of flour remaining. Do not overmix - this is what keeps pancakes tender instead of tough.

Gently fold in the chocolate chips, distributing them evenly without overworking the batter. Let the batter rest for 2 minutes while the skillet finishes heating.

Scoop about 1/3 cup batter per pancake onto the hot skillet, leaving 2 inches between each. Cook until bubbles form on the surface and the edges look set, about 2 to 3 minutes. Flip and cook until golden brown on the second side, about 1 to 2 minutes more. Adjust heat as needed - if they brown too fast, lower the heat. Transfer to a plate and cover loosely with foil to keep warm. Repeat with remaining batter, greasing the pan as needed between batches.

Serve immediately with extra chocolate chips on top, warm maple syrup, and a pat of butter if desired. These are best eaten right off the griddle while the chocolate is still melty.