Combine water, sugar, and yeast in a large mixing bowl and let sit for a few minutes until foamy.
Add salt and flour to the yeast mixture. Stir with a wooden spoon until combined, then mix in the olive oil.
Cover the dough loosely with a kitchen towel and let it rise in a warm place for about 1 hour or until doubled in size.
Punch down the risen dough and shape it into a smooth round loaf. Place a piece of parchment paper in the slow cooker and place the dough on top.
Cover the slow cooker with its lid. Set the cooker to high and cook the bread for about 2 hours, or until a thermometer reads 190°F when inserted into the middle of the bread.
For a crispier crust, after the bread is done in the slow cooker, place it under the broiler for about 2-4 minutes.
Remove the bread from the slow cooker and let it cool on a wire rack before slicing.