01 - Fill the steamer pot with water and bring it to a gentle simmer. Line cupcake molds or silicone cups with paper liners, ensuring they are ready for the batter.
02 - In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt until thoroughly combined. Set aside.
03 - Crack the eggs into a large mixing bowl and add the granulated sugar. Beat vigorously until the mixture becomes pale and thickened. Pour in the whole milk, melted unsalted butter, and vanilla extract. Mix until fully incorporated.
04 - Gradually add the dry ingredient mixture to the wet ingredients, folding gently with a spatula. Mix only until just combined—stop as soon as the flour streaks disappear to avoid developing gluten which would make cupcakes dense.
05 - For the blooming color effect, divide the batter into separate bowls and fold in your chosen food coloring. Layer the different colored batters in the molds or swirl gently with a toothpick for a marbled appearance.
06 - Spoon the batter into the prepared cupcake molds, filling each one about three-quarters full. This allows room for the cupcakes to rise and form their characteristic bloomed top.
07 - Arrange the filled molds in the steamer, leaving adequate space between each for proper steam circulation. Wrap the steamer lid with a clean kitchen cloth to catch condensation and prevent water from dripping onto the cupcakes.
08 - Steam over medium heat for 12 to 15 minutes. The cupcakes are done when a toothpick inserted into the center comes out clean and the tops have cracked open creating the bloomed effect.
09 - Carefully remove the cupcakes from the steamer and let them cool in the molds for a few minutes. Transfer to a wire rack to cool completely, then decorate with sprinkles, edible flowers, or chocolate chips as desired.