In a mixer, with a dough hook, combine the flour with the diastatic malt powder.
Proof the yeast by whisking it into the warm (not hot) water. It should bubble and foam. If the yeast clumps all together and floats on top it is dead and you will need to get new yeast.
Add 1 cup of the ice cold water to the mixing bowl, while mixing on a low speed.
Mix for about 1 minute, and then add in the warm water/yeast mixture. Use the remaining ¼ cup of cold water to swirl around the bowl the yeast water was in, to get any last bit of yeast that may be stuck to the bowl, and add to the mixer.
Continue to mix for about 1 minute, scraping down the sides of the bowl if needed.
Add in the salt, and mix on low for about 1 minute, then add in the olive oil and mix until combined, about another 1-2 minutes.
On a clean work surface knead the dough for about 2-3 minutes then place on an oiled cookie sheet and cover with a damp cloth. Let rise for about 1 hour in a warm spot on the counter.
In an 18x12 (slightly thinner crust) or 15x10 (slightly thicker crust) pan, add ¼ cup of olive oil. Spread the oil to cover the entire bottom of the pan.
Add the dough to the pan and using your fingers, work to spread the dough out to fill the pan. Flip over to make sure both sides are oiled. The dough may not stay shaped to reach the corners at this point. Let the dough set for about 1 hour.
After 1 hour, again stretch the dough to try to reach the corners of the pan. This will also serve to degas the dough.
Let the dough rise for another hour. Do not degas or handle the dough any further at this point.
Preheat an oven to 450 degrees.
Par-bake the dough by cooking it for 15 minutes, turning it about 180 degrees half way through the cook time.
Remove the dough to a wire cooling rack until ready to use. The dough will keep fine for a couple of hours, but beyond that you will want to cover it with some plastic wrap to keep it from drying out. If you do not plan on using the dough for more than 10 hours, it should be covered and refrigerated.