Add oil to a Dutch oven. Add candy thermometer to the side of the oven. Place over medium heat so that it reaches 350 degrees. This will take about 20 minutes.
Cut the ends off the loaf so the loaf is all the same width. Slice loaf into 3-inch slices. You should get 4 pieces on a medium (12-inch) loaf. Grab one slice and stand it up so the top of the bread is pointed to the sky. Create a slit at the top through the middle of the bread slice without cutting through to the bottom. Use your fingers to gently make some space in the slit for the bananas to go. Repeat with the other 3 slices.
Grab the bananas and slice in half lengthwise and then width wise. You should have 8 pieces. Then cut each piece into equal halves again to make 16 slices (4 slices per piece of bread). Stuff 4 slices of banana into the slits of each piece of bread, forcing it in gently.
Make the custard by first adding the sugar, salt, and cinnamon to a shallow bowl and whisking together. Then, add eggs and whisk into sugar mixture. Finally add, the milk mix together. Fill another shallow bowl with the ¾ cup of sugar and 2 teaspoons of cinnamon. Mix together and set aside.
Once the oil is at 350 degrees, dip one of the banana-stuffed toasts into the custard. Flip and let the other side absorb some of the custard. Pull toast from custard using tongs and let excess drip off. Place toast into hot oil and fry for 2 minutes. Then, flip toast and fry for 2 more minutes. Remove from oil and let drain on a cooling rack for 1 minute and then dip into cinnamon sugar mixture. Cover with cinnamon sugar. Serve immediately with strawberry compote (recipe below). Repeat with 3 remaining toasts.