Preheat oven to 400°F (200°C). In a blender, combine oats, almond milk, maple syrup, baking powder, vanilla and salt. Blend until you have a smooth batter.
Take 1/4 cup of the batter and mix with brown sugar and cinnamon. Put the cinnamon sugar batter in a small plastic bag with the corner snipped.
Pour half the base batter into a greased 10-12oz ramekin. Spread into an even layer. Using the plastic bag like a piping bag, pipe a cinnamon swirl on top. Add the remaining base batter and smooth into a flat layer. Top with another cinnamon swirl.
Bake at 400°F (200°C) for 15-20 minutes. Allow to cool 5-10 minutes.
While oat cake is baking, whisk together cream cheese, powdered sugar and vanilla. Drizzle on top of the oat cake and enjoy!