In a large bowl, combine warm water, instant yeast, and sugar. Let it sit for 5-10 minutes until frothy.

Gradually add all-purpose flour, salt, and olive oil while mixing until a shaggy dough forms.

Transfer the dough to a floured surface and knead for 5-10 minutes until smooth and elastic.

Place the dough in a greased bowl, cover, and let it rise in a warm place for about 1 hour.

Prepare the filling by mixing cinnamon with brown sugar in a small bowl.

Once risen, gently punch the dough down and roll it into a rectangle about 1/2 inch thick.

Spread the cinnamon and brown sugar mixture evenly across the dough, then roll it tightly into a log.

Twist the log to create swirls and place seam-side down in a greased baking pan.

Cover the pan and let it rise for about 30 minutes.

Preheat your oven to 375°F (190°C). Bake for 25-30 minutes until golden brown.

Let the focaccia cool in the pan for 5-10 minutes before serving, optionally dusting with powdered sugar.