Preheat the griddle or pan over medium heat. In a medium bowl, whisk together the flour, baking powder and salt. Whisk in the milk, egg and oil, just until the batter has combined. Place a third of the batter into a separate bowl and add a few drops of your food coloring, stir to combine. Pour the colored batter into a ziptop bag and cut a small hole on the bottom corner of the bag. Grease the pan with butter. Pour about 1/3 cup of the plain pancake batter on the pan. With your ziptop bag draw a heart on top of the pancake. Cook the pancake 2 to 3 minutes, or until the bubbles begin popping on top of the pancake and it’s golden brown on the bottom. Flip the pancake over. Cook an additional 2 to 3 minutes, until the other side is golden as well.