Preheat the oven to 350°F. Brush a 9 x 9 x 2-inch pan with melted coconut oil or butter. In a medium mixing bowl, combine the flour, sugar, baking powder and salt. Add the coconut milk, butter, egg and vanilla, whisk until smooth. Evenly pour the batter into your prepared baking pan.
Top the batter evenly with blueberries.
In a small bowl, beat the eggs till frothy, then add in ricotta cheese, sugar and vanilla. Whisk together well. Spread mixture evenly over the blueberries.
Bake the cake for 55 to 60 minutes, or until its golden brown around the edges. Remove from the oven and serve warm or at room temperature.