Whisk together buttermilk and egg in a medium bowl.

In a separate medium bowl, combine oats, flour, sugar, baking soda, 1/2 teaspoon cinnamon, and salt.

Stir the dry mixture into the wet mixture and let stand for 15 minutes. The mixture will bubble slightly as it sits.

Place raspberries, maple syrup, and remaining cinnamon in a small saucepan. Bring to a simmer over medium heat and cook 3-5 minutes until the berries are mostly broken down, stirring occasionally. Remove from heat and cover to keep warm.

Coat a griddle or large nonstick skillet with cooking spray; heat over medium heat.

Using 1/4 cup of batter for each, cook the oatcakes for 2-3 minutes until bubbles dot the surface. Flip and continue cooking 1-2 minutes more until browned and cooked through. Reduce heat if necessary to prevent over-browning.

Serve the oatcakes with the raspberry sauce drizzled over top or on the side for dipping.