01 - Fill steamer pot with water and bring to a gentle simmer. Line cupcake molds or silicone cups with paper liners, ensuring they are ready for batter.
02 - In a medium bowl, whisk together all-purpose flour, baking powder, baking soda, and salt until evenly distributed. Set aside for later use.
03 - In a separate large bowl, beat eggs and granulated sugar until the mixture becomes pale and thickened. Pour in whole milk, melted unsalted butter, and vanilla extract. Mix thoroughly until fully incorporated.
04 - Gradually add the dry ingredient mixture into the wet ingredients, folding gently with a spatula until just combined. Avoid overmixing to maintain tender texture. A few small lumps are acceptable.
05 - For the blooming color effect, divide batter into portions and fold in desired food coloring. Layer or swirl different colored batters in the molds to create a marbled appearance.
06 - Spoon the batter into prepared cupcake molds, filling each approximately three-quarters full to allow room for rising during steaming.
07 - Arrange filled molds in the steamer with adequate space between each for proper steam circulation. Cover the steamer lid with a clean kitchen cloth to prevent condensation droplets from falling onto the cupcakes. Steam over medium heat for 12 to 15 minutes, or until a toothpick inserted into the center comes out clean and the tops have developed the characteristic bloomed, cracked appearance.
08 - Carefully remove cupcakes from the steamer and allow to cool slightly in the molds. Once cooled, decorate with sprinkles, edible flowers, or chocolate chips as desired.