Preheat the oven to 350º. Prepare your baking pans by generously buttering them. For some extra insurance against sticking, you can cut parchment paper to fit the bottoms of the pans, place in the bottom of each and butter again.

In a large bowl, whisk together all of the dry ingredients: the flours, wheat germ, sugar, baking powder and soda, nutmeg, cinnamon, ginger, allspice and salt.

In a separate large bowl, whisk together the pureed squash, molasses, eggs, vegetable oil, yogurt, milk and lemon juice and zest.

Empty the wet ingredients into the dry ones and mix together, just until the dry ingredients are incorporated. It will not be a smooth batter, but that is what you want - over-mixing will result in a less tender final result.

Divide the batter evenly in the prepared pans. Bake on the center rack of the oven, turning the loaves a few times during the baking time to ensure even cooking.

The smaller loaves will be done in around 30 minutes, the larger ones in 50 to 55 minutes. Test with a toothpick or wooden skewer, which should come out clean with the loaves are done. Alternatively, you can test for temperature, with a digital thermometer, which should read 200º.

Cool the loaves in the pans for about 5 minutes, and then carefully tip out onto a cooling rack - it's a good idea to run a table knife around the edges of each pan before removing the loaves.

Cool completely before wrapping tightly for storage. They will be fine at room temperature for a couple days, but after that should be refrigerated or frozen for longer term storage.