Soak popcorn in milk for about 2 hours. Refrigerate if soaking longer, but bring to room temperature before using.

Strain popcorn through a fine-mesh strainer, pressing to extract all the liquid. Discard the solids.

Preheat oven to 350°F (175°C) and line a 12-cup cupcake or muffin pan with liners.

In a mixer bowl, combine flour, sugar, baking powder, salt, and chive petals. Mix briefly.

Add 1 1/4 cups of the strained popcorn milk and butter to the flour mixture. Beat on medium-low speed for about 2 minutes.

In a separate bowl, whisk egg yolks and vanilla into the remaining 3/4 cup strained popcorn milk.

Gradually add the egg yolk mixture to the batter, scraping down the sides of the bowl as needed.

Fill the muffin cups two-thirds full with batter.

Bake cupcakes for about 20 minutes, or until a toothpick inserted into the center comes out clean.

Let cool on a wire rack.

For the frosting, beat cream cheese, butter, confectioners' sugar, and vanilla with a mixer on medium speed for 3 to 5 minutes, until smooth.

Frost each cupcake and top with chive blossom petals, if desired.

Serve immediately.