Preheat oven to 350˚. Cream the butter, sugar, honey and molasses. Add the egg and beat well. In a separate bowl mix the dry ingredients together. Alternate mixing the flour mixture and the yogurt to the butter mixture until just combined. Place 2 heaping tablespoons of the batter into muffin tins. Bake for 25–28 minutes, until a toothpick comes out clean. Allow to cool completely before frosting.
To make the frosting, in a mixing bowl cream the butter, sugar, milk, vanilla and salt together. Pick only the flowers off of the milkweed flower heads. After frosting the cupcake, arrange the flowers on top of each cupcake. Serve.