Put 8 raspberries on the side for later.
To make sauce combine the raspberries, 1/2 cup sugar and lemon juice in a blender and blend on liquefy until smooth. Strain through a fine mesh sleeve. Whisk in additional sugar if desired.
To make the French toast, beat the eggs with the milk, vanilla, sugar and salt in a large shallow bowl. Working in two batches, melt half of the butter in a large non-stick skillet over medium high heat or heat a griddle to medium hot. Dip half the bread slices quickly in the egg mixture until slightly soaked.
Transfer to skillet and sprinkle each slice with a quarter chocolate chips. Dip the remaining bread into the egg mixture and place on top of chocolate press gently but firmly with a spatula to adhere the slices.
Turn down the heat to medium low and cook turning once until well browned and cooked through, 5 minutes per side.
Serve on warmed plates sprinkled with a little additional confectioners' sugar. Spoon a small amount of raspberry sauce around the toast and garnish with 2 whole raspberries and a sprig of mint. Serve the remaining sauce on the side.