Prepare the dandelion infusion: In a small pot, bring 1/2 cup of water to a boil. Add the dried dandelion petals and steep for 5-10 minutes. Strain out the petals and reserve the liquid.

Bloom the gelatin: In a medium mixing bowl, pour the dandelion infusion and sprinkle the gelatin over it. Let it sit for about 5 minutes to bloom.

Make the syrup: Combine honey with the remaining 1/4 cup water in a saucepan. Bring to a gentle simmer until honey is dissolved and the syrup reaches 240°F (115°C).

Combine the mixture: Slowly pour the syrup into the bloomed gelatin, stirring constantly.

Whisk the marshmallow base: Using an electric mixer, whisk the mixture on medium speed. Gradually increase the speed and whisk for 10 minutes, until the marshmallow becomes thick and fluffy.

Add vanilla: Add the vanilla extract and a pinch of salt, whisking to combine.

Prepare the mold: Mix powdered sugar and cornstarch. Dust a baking pan or shallow dish with the mixture.

Transfer the marshmallow mixture: Pour the marshmallow base into the pan, smoothing the top with a spatula. Let it sit at room temperature for at least 4 hours or overnight to set.

Cut the marshmallows: Dust a surface with the powdered sugar-cornstarch mix. Turn the marshmallow slab out and cut into squares.

Finish: Toss marshmallow pieces in the powdered sugar-cornstarch mixture. Store or serve immediately.