Hong Kong French Toast

Spread half of the peanut butter evenly between 6 slices of bread, stacking them to form a tall 6-layer sandwich with peanut butter between each layer. Repeat with the remaining 6 slices to make a second insanely-tall sandwich.
Press each sandwich gently to help it hold together, then trim the crusts from all sides to create clean, tall rectangular blocks.
In a wide, shallow bowl, whisk together the plant-based milk, vanilla extract, cinnamon, starch, and salt until smooth and fully combined.
If preparing the optional coconut condensed milk, combine the coconut milk, starch, sugar, vanilla powder or extract, and salt in a small saucepan. Whisk thoroughly to dissolve the starch. Place the pan over medium heat and cook for 5–7 minutes, whisking continuously, until the mixture thickens. Remove from the heat and set aside.
Heat the oil in a skillet over medium heat. After 2 minutes, when the oil is hot, lower one sandwich into the batter, coating all sides evenly. Let the excess batter drip off before transferring it to the skillet. Repeat with the second sandwich if space allows, without overcrowding.
Fry each sandwich for 2–3 minutes per side, including the edges, until golden and crisp on all surfaces.
Transfer to a wire rack to cool and drip dry for a couple of minutes.
Plate the fresh toast, topping with a pat of vegan butter and drizzling with maple syrup and optional coconut condensed milk. Dust with powdered sugar just before serving. Serve warm.