What do you think of this recipe

Hey I found a recipe for gingerbread I'm building a house and was wondering if anyone has tried this one and if its any good.

1/2 c barley malt syrup
1/2 c dark brown sugar
4 egg whites
vanilla extract

3 c rye flour
1/2 tsp baking powder
1 tsp ginger
1 tso cinnamon
1 tsp all spice