1. Preheat the oven to 450 degrees and grease either a 12 muffin tin or two six muffin tins.
2. Whisk 2 cups of flour of choice (I like 1 cup of sorghum flour with 1 cup of arrowroot flour) with 1/2 tsp salt and 1/2 tsp cardamom. Set aside.
3. Using a fork mix the equivalent of 1 cup of eggs (4 large whole eggs, 1, 2, or 3 whole eggs plus enough liquid egg whites to make 1 cup) just until the eggs are light and uniform in color.
4. Add 1 1/4 cup milk (I prefer flax or soy milk) and 3/4 cup cooked, pureed squash to the eggs. Whisk the wet ingredients with the dry just until blended. There will be lumps, and that is how you want it.
5. Transfer the batter (which will be thin and runny) to a spouted measuring cup large enough to hold all the batter. Evenly divide the batter among 12 muffin tins.
6. Put the muffin tin into the oven and bake for 30 minutes. Do not open the oven door at any time during the 30 minutes. After 30 minutes, you can pierce the popovers to release steam and then remove the popovers to a wire cooling rack or towel-lined bowl or directly to the plates.