2. In a mixing bowl, combine flour, espresso powder, and salt. Mix well.
3. In a separate bowl beat eggs whites until foamy on top.
4. Gradually add sugar, and vanilla. Whisk until soft peaks form.
5. Whisk constantly and add flour mixture into the bowl with egg.
6. Throw chocolate and fold to combine.
7. Into an ungreased baking pan, transfer the mixture. With a knife remove air bubbles, if any from the batter.
8. Pop the pan in oven and bake for 35 minutes. Remove the pan from heat and allow it to cool.
9. Cut into slices and serve angel food cake with dark chocolate sauce, strawberry and powdered sugar garnish.
Do not use a plastic bowl to beat egg as they retain oil. Make sure that the bowl is dry. Dry bowl help egg whites to maintain its perfect texture.
Cool the cake upside down so that it smoothly comes out of the pan.