Puréed carrots get the company-best treatment with a little butter, sugar, and maple flavoring. You'll love the soufflé-like texture. An Instant Pot and a food processor make assembly quick and easy, but neither is essential. Make it gluten-free by using gluten-free flour.
Steam carrots: Steam 1 pound scrubbed carrots (cut in 1/2 to 3/4 inch chunks) in an Instant Pot (5 minutes, natural release) or on the stovetop until tender.
Purée: Process carrots in a food processor or mixer until smooth.
Add remaining ingredients: Blend in 3 tablespoons all-purpose flour, ⅓ cup granulated sugar, 1 teaspoon table or sea salt, 1/2 teaspoon maple (or vanilla extract), 3 large eggs, and ¼ cup butter, cut in chunks, and mix until smooth. Alternatively, use a stand mixer or immersion blender for this step.
Bake: Pour into a medium oven-safe buttered casserole dish. Bake at 400˚F (200˚C) for 15 minutes. Reduce heat to 350˚F (180C) and continue baking for 45 minutes more, until set.
Serve immediately.
Notes
Make ahead: Prepare the casserole up to one day in advance. Cover and refrigerate before baking. Bring to room temperature, then bake as directed.