Prepare the custard: In a shallow bowl, whisk together the egg, oat milk, vanilla extract, and 1 tbsp of the ground cinnamon. Ensure the mixture is well combined.
Heat the pan: Melt the vegan butter in a non-stick frying pan over medium heat. Make sure the pan is hot enough to sizzle a drop of water before proceeding.
Dip and cook: Dip the assembled bread into the custard mixture, ensuring both sides are coated evenly. Let any excess drip off before carefully adding it to the hot pan. Cook for 2-3 minutes per side, or until golden brown and cooked through.
Assemble and serve: Transfer the cooked French toast to a plate. Dollop half of the coconut whipped cream on top.
Spread the mashed raspberries evenly onto one slice of bread. Top with desired whole raspberries. Carefully place the other bread slice on top, gently pressing to create a "sandwich."
Sprinkle with a pinch of cinnamon.
Garnish with additional whole raspberries and enjoy!