Step 1In a blender, combine the flour, water, salt, cumin and 1 1/2 tablespoons oil until smooth. Remove to a bowl and set aside the batter to rest for at least 2 hours, covered, at room temperature.
Step 2To cook, heat the broiler in your oven. Oil a 9- or 10-inch pan (or cast-iron skillet, or tart pan) with the remaining tablespoon olive oil and heat the pan in the oven.
Step 3Once the pan and the oven are blazing hot, pour enough batter into the pan to cover the bottom, swirl it around, then pop it back in the oven.
Step 4Bake until the socca is firm and beginning to blister and burn, about 2 to 3 minutes. The exact time will depend on your broiler.
Step 5Slide the socca out of the pan onto a cutting board, slice into pieces, then shower it with coarse salt, pepper and a drizzle of olive oil.
Step 6Cook the remaining socca batter the same way, adding a touch more oil to the pan between each one.