In a large bowl, whisk together the flour, baking powder, salt, and sugar.
Melt 3 tablespoons of the butter and let it cool slightly. In a separate bowl, whisk together the melted butter, eggs, milk, and vanilla extract.
Gradually add the wet ingredients to the dry ingredients and stir until just combined. Do not overmix; a few lumps are fine.
Gently fold in the raspberries. Let the batter rest for 5 minutes.
Heat a large skillet or griddle over medium heat. Melt the remaining tablespoon of butter on the cooking surface.
Pour about ¼ cup of batter onto the hot skillet for each pancake, spacing them a few inches apart. Cook in batches if necessary.
Cook for 1–2 minutes, until bubbles form on the surface and the edges begin to set.
Flip the pancakes once and cook for another 1–2 minutes, until golden brown and cooked through.
Serve warm with butter, syrup, or your favorite pancake toppings.
Notes
Make sure to not over mix the pancake batter. Mix just until the wet and dry ingredients are combined.Refrigerate the leftover pancakes in an airtight container for up to 5 days or you can freeze the pancakes for up to 3 months.Make sure that the melted butter has cooled to room temperature so that it does not cook the eggs once they are mixed into the butter.