Remove the dandelion petals from the blooms. Be careful to only get the yellow petals since the greens can have a bitter flavor. (See notes above for tips on doing this easily.) You need 1 cup of just petals. This took me about 22 dandelions, but this will vary depending on the size of the blooms.
Wash the petals and mound on a paper towel to dry.
Next, cream together the butter, sugar, egg, and honey using a stand mixer or by hand. If you only have a large egg, break it separately in a small bowl. Whisk it well using a fork, then add half in the whisked egg to the batter.
Once that mixture is light and fluffy, add the salt and vanilla. Mix until combined.
Now add in the dandelion petals. They don't have to be completely dry, just not dripping wet.
Finally, add the flour, only mixing until just combined. This might be easier to do by hand as opposed to using a mixer.
Place the dough onto a large sheet of plastic wrap and shape into a log that is about 2 inches in diameter. Wrap the dough tightly with the extra plastic wrap and place it in your refrigerator for a few hours or until the dough is stiff. You can also leave it overnight.
When you are ready for baking, preheat the oven to 350º. Remove the dough from the plastic wrap and cut it into slices that are between ⅛ and ¼ inch thick. Place the slices spaced about 2 inches apart on a baking sheet covered with parchment paper.
Bake in the preheated oven for 12 to 15 minutes or until the edges are slightly brown. (The cookies might take a bit longer depending on the size of your slices.) Allow the cookies to cool before removing them from the parchment paper. Store any leftovers in a sealed container. Enjoy!