How many calories in this chocolate loaf? I had two slices.

Here are the ingredients:
1 1/2 cups oats flour.
1/3 cup cocoa powder
1 tsp baking powder
1/4 cup sugar
2 eggs
1/2 cup Greek yogurt
1/4 cup maple syrup
1 tsp vanilla extract
2 tablespoons milk

Chocolate frosting: 3 small dark Galaxy melted chocolate bars with two tablespoons of low fat yogurt