This looks like the first pollinated squash in the Three Sisters bed:
It's bigger than the babies that dried up after they didn't get pollinated.
I tried to pollinate zucchinis, but the pollen from this plant didn't work and we didn't have male and female zucchini flowers at the same time.
From the Farmers' Almanac:
14th-15th Plant Tomatoes, Beans, Peppers, Corn, Cotton, And Other Above Ground Crops On These Most Fruitful Days. Plant Seedbeds And Flower Gardens
We'll try to get some more planting areas ready today.