Add the softened butter to the bowl of a stand mixer fitted with the whisk attachment, or use a hand mixer. Beat on medium-high speed for 2 minutes until light and fluffy. Add the honey and kosher salt. Continue whipping for 2 to 3 minutes until smooth, airy, and silky.

Transfer the whipped honey butter to a piping bag or spoon it into 8 to 10 large shell-shaped silicone molds, smoothing the tops.

Freeze for 1-2 hours, or until firm enough to unmold cleanly.

Carefully arrange on a serving platter. Finish each shell with a sprinkle of flaky sea salt. Serve with warm, toasted baguette slices.