Bar crust:
1 box sugar free devil's food cake mix, minus 1 cup
1/2 cup melted butter
1 egg
Filling:
24 oz frozen raspberries, partially thawed
1 cup granulated Splenda
1/2 cup flour
Topping:
1 cup cake mix
1/4 cup Splenda
1/4 cup softened butter
1 tsp ground cinnamon
1/2 cup sugar free chocolate chips (optional)
Preheat oven to 350°F.
Grease a 13x9" pan.
Reserve 1 cup of cake mix for the crumble topping.
Combine remaining cake mix, melted butter, and egg to make a stiff dough. Pat dough into an even layer on the bottom of the prepared pan; set aside.
Combine partially thawed raspberries (you want them to be wet), Splenda, and flour. Spread evenly over the crust.
Combine reserved 1 cup of cake mix, 1/4 cup Splenda, softened butter, and cinnamon into a thick paste. Crumble evenly over the raspberry filling.
Bake for 50-60 minutes, until a tooth pick inserted in the center has no cake at the tip. Remove from the oven and immediately sprinkle with chocolate chips, if you are using them. (You could also add them about 5-10 minutes before baking is complete.)
Cool completely before cutting.
Makes 24 bars.
There are 28 grams of sugar in 24 ounces of raspberries so these bars can't legally be labeled sugar free (since they have more than 1 g of sugar).