Preheat the oven to 425°F.
Grease a 13x18-inch half-sheet tray with cooking spray. Line the tray with parchment paper or, if available, use a silicone baking mat.
In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, baking powder, and salt until evenly combined.
In a separate mixing bowl, whisk together the milk, eggs, melted butter, and vanilla extract until fully blended.
Pour the wet ingredients into the dry ingredients.
Using a spatula, gently mix by hand until the batter is just combined. Do not overmix; a few small lumps are acceptable and help maintain a tender pancake texture.
Pour the pancake batter into the prepared sheet pan.
Spread the batter evenly with a rubber spatula, ensuring it reaches all corners of the pan.
Gently tap the tray on the counter several times to release any large air bubbles.
If using toppings, distribute the desired toppings evenly over the batter. Toppings may be arranged in separate sections for variety or spread over the entire pan.
If using warmed peanut butter, Nutella, Biscoff, or jam, drizzle it lightly over the batter and swirl gently with a knife or skewer.
Bake for 12 to 15 minutes, or until the pancakes are lightly golden and the center is set.
Remove the pan from the oven and allow the pancakes to cool slightly before slicing.
Slice into squares or rectangles.
Serve warm with maple syrup, butter, fresh fruit, whipped cream, or additional desired toppings.