Prepare a 10-inch cast iron skillet by rubbing it liberally with non-dairy butter and and adding a tablespoon of canola oil into the center of it.
In the bowl of a stand mixer fitted with the dough hook attachment, combine water, yeast and brown sugar. Stir and set aside for 5 minutes to allow the yeast time to bloom.
Add the flour and salt into the bowl and turn the mixer on low speed until everything is combined. You may need to stop the mixer and scrape the sides of the bowl down.
Once everything is combined, turn the mixer to medium speed, and mix the dough for 5 minutes. After 5 minutes, scrape the dough into the prepared cast iron pan. Turn the dough over to coat it in the oil, then cover with plastic wrap and leave it at room temperature for 1 ½-2 hours or until the dough doubles in size.
In a medium bowl, combine melted non dairy butter, brown sugar, cinnamon and a pinch of salt. Mix to combine.
Remove the plastic wrap for the focaccia dough. Dollop a heaping ⅓ cup of the cinnamon filling on top of the dough. Use the back of a spoon to spread over the surface of the dough.
Then, fold the bottom ⅓ of the dough into the center and the top ⅓ of the dough on top of that. Like folding a letter.
Top the dough with the remaining cinnamon filling and spread it out with a spoon. Place plastic wrap on top of the skillet and allow the dough to rise for 30 more minutes.
Preheat oven to 400* F.
After the focaccia has risen for 30 minutes, oil your hands and use your fingers to dimple the dough evenly all over. See note! Some of the cinnamon sugar will stick to your hands and thats okay.
Bake the focaccia in a 400*F oven for 30-33 minutes or until the focaccia is golden around the edges and across the top.
In a medium bowl, combine powdered sugar, non-dairy milk and vanilla. Whisk until completely smooth. Use a spoon to drizzle the glaze over the warm focaccia and serve!
