Place a double layer of cheesecloth over a colander and set it over a plate or bowl. Scoop yogurt into the cheesecloth and let it strain for 4 hours.
Slice challah bread into 12 -1 ½ in slices. Place bread slices on a baking sheet and toast each side under a broiler, or use a grill to get it all nice and toasty. Using a standard broiler you will only need 1-2 minutes on each side.
Using a kitchen stand or hand mixer, whip strained yogurt and mascarpone together until smooth and fluffy.
In a separate bowl gently stir blueberries, raspberries, strawberries and cherries until their own juices begin to lightly coat themselves.
Divide the yogurt mixture evenly onto the 12 slices of bread. Carefully scoop some berries out and place them on top of the yogurt.
Drizzle with 2 teaspoons each with honey and serve.