In a large bowl, add eggs, egg whites, sugar, salt,almond extract, and vanilla.
Whisk by hand until frothy.
Add the almond flour and mix until a smooth batter forms.
Pour batter into the prepared cake pan and smooth the top with offset spatula.
Sprinkle ⅓ cup Turbinado sugar over the top evenly.
Sprinkle ⅓ cup slivered almonds over the sugar layer and try to evenly cover the surface.
Bake in a 350°F preheated oven on the middle rack for 45 to 55 minutes.
Let it cool on a rack until it comes to room temperature.
When cool, run a knife around the edges and invert on a rack and turn it over again the right side up on a plate. Now you are ready to cut into wedges and serve it .