Harvest and clean the petals: Gather dandelion blooms away from roads and treated lawns. Pluck the yellow petals from the green base and rinse them gently in cool water to remove grit and tiny visitors.

Steep the petals: Bring 4 cups water to a simmer, add the petals, and remove from heat. Cover and let steep for 20–30 minutes until the water is deeply golden and fragrant. Strain through a fine sieve or cheesecloth, pressing to extract every drop of floral liquid.

Measure and prepare: Measure 4 cups of the dandelion infusion. If it's less, top with water to reach 4 cups. Return the liquid to a heavy-bottomed pot. Stir in lemon juice and powdered pectin until dissolved.

Bring to a rolling boil: Over high heat, bring the mixture to a full, rolling boil. This boil should not stop when stirred. If using vanilla bean, add the split bean now to infuse.

Add sugar and finish: Quickly add 4 cups of sugar, stirring constantly. Return to a rolling boil and boil hard for 1 minute while stirring. Remove from heat, skim off any foam for clarity, and stir in vanilla extract if using.

Ladle the hot jelly into sterilized jars, leaving 1/4-inch headspace. Wipe rims clean, seal, and process in a boiling water bath for 5–10 minutes depending on altitude and jar size.

Let jars cool completely. The jelly will set into a delicate, translucent gold that looks like liquid sunshine.