Grease 2 (9-inch) loaf pans

Cook 2 cups of berries with ¼ cup water, granulated sugar and brown sugar until a thick puree. Cool slightly and fold in remaining berries, add cinnamon and zest if using. Cool completely.

Divide challah dough in half.  Roll out 2 pieces into ¼ thick 10-inch circle. 

Schmear each circle with 1/2 of the filling.

 Roll circles, jelly roll style into long cigars.

 Split each cigar, down the center, while keeping the top (about 2-inches attached).

 Twist cigars together and fold ends under.

Place into greased pan. 

 Cover with a towel and let rise for 1-1 ½ hours until doubled. Repeat with remaining dough.

Preheat oven to 350F.  Brush babkas with egg wash and sprinkle each with tablespoon of sugar. Bake for 20 minutes. Rotate pans and continue baking for another 10-15 minutes or until a wooden skewer can be easily inserted.