Air marble cake with strawberry sauce

Ingredients:
Dough:
Butter - 110 g
Sugar - 1 cup
Light cream (or plain yogurt (non-Greek)) - 1 cup
Vanilla - 1 teaspoon
Baking powder - 1 tsp
Flour - 1.5 cups
4 egg whites
Dark chocolate - 60 g

Preparation:

1. Heat the oven to 175 degrees and grease a baking pan with butter, sprinkle with flour.
2. Beat butter with sugar until light air conditions, add the cream vanilla. Mix.
3. Sift flour and baking powder together, then gradually add in the bulk.
4. Protein shake to stable peaks. Gradually enter into the bulk and mix gently to proteins are not settled.
5. In a small bowl pour 1/3 dough and mix with the melted chocolate until smooth.
6. Pour half of the white batter into the pan, smooth shoulder. Pour the chocolate batter and close the remaining vanilla (do not stir yet). Now take a knife light pattern on the wet test (S or back and forth in a zig-zag). But do not overdo it, or not get the effect of marble.
7.Vypekayte about 35 minutes.

Klubchnichny sauce:
Strawberry - 900 g - 1 kg (chopped)
Sugar - ¼ cup
Water - ¼ cup
Fresh lemon juice - 2 tablespoons

Preparation:
Put all ingredients in a saucepan over medium heat and bring to a boil. Let cool and serve with cake.