In a large bowl, whisk together flour, sugar, baking powder, baking soda, and salt. Set aside.
In another bowl, whisk together milk, eggs, and vanilla until lightly frothed.
Make a well in the center of the dry ingredients and pour in the wet ingredients. Stir until just blended; a few lumps is OK.
Let batter rest for at least 15 minutes. Meanwhile, melt the butter in a microwave-safe bowl and set aside to cool.
Preheat your electric griddle to 350°F or set a skillet over medium heat. Once heated, stir the melted butter and chocolate chips into the batter.
Pour batter by 1/3 cupfuls onto griddle and cook until bubbles form and edges start to look dry. Flip and cook the other side until golden brown. Repeat with remaining batter.
Notes
Vegetable oil can be swapped in for the butter. You'll need 1/4 cup.