Loaf pan focaccia: add flour, salt, and yeast to a medium-sized bowl and stir all dry ingredients until thoroughly combined.
Measure and add 7 grams of olive oil (2 teaspoons) and water, and stir for 2 minutes to ensure that all dough components are combined and there are no dry flour spots. The dough will be very sticky and probably difficult to handle with your hands, so keep using the spoon.
Spray the inside of an 8x4-inch loaf pan with non-stick cooking spray and then add 2 teaspoons or 8 grams of olive oil to the pan and tilt the pan a few times to allow the olive oil to spread out some.
Add the sticky dough on top of the olive oil in the pan and moisten your fingertips with some of the olive oil to prevent sticking. Using your olive-oiled fingertips, press the dough to flatten it and try to get the dough to reach close to all four corners of the pan. Flipping the dough after you've flattened it will help to coat the dough thoroughly with olive oil and make it easier to handle with your fingers.
Once the dough is flattened and stretching close to the corners of the pan, cover the pan and allow it to rise for 1.5 to 2 hours or until it is really puffy and at least doubled in size.
Near the end of the rise time, preheat your oven to 450 degrees F (230 C).
Your dough should already be fairly dimpled from flattening it and stretching it out earlier, but after it has doubled, you can dimple the top lightly if you'd like. Try not to dimple all the way through the dough to the bottom because that will deflate the bread.
Add a drizzle of olive oil to the top and then sprinkle it with salt and pepper. This is the chance to add any other herbs and seasonings that you might desire.
Bake the focaccia for 18 to 23 minutes.
Remove from the pan to a cooling rack to cool before slicing.
Fig and balsamic dressing: combine all dressing ingredients in a small bowl and whisk to combine.
Sandwich assembly: toss the arugula in the bowl with the fig and balsamic dressing.
Slice the focaccia and spread fig preserves on the bottom slice of bread.
Top the preserves with piled-up prosciutto and then layers of cantaloupe. Lightly salt the cantaloupe if desired and then drizzle on balsamic glaze.
Add dressed arugula to the top and then close the sandwich with the top slice of focaccia. Serve and enjoy.