Can I add more sugar to  this recipe?

Chocolate Cake

1 1/2 sticks (3/4 cup) unsalted butter, softened

6 oz unsweetened baking chocolate, coarsely chopped

1 1/2 cups sugar

2 tsp baking powder

2 tsp vanilla extract

4 large eggs

2 1/4 cups all-purpose flour

1 cup milk

Most cake recipes have almost as much sugar as flour, only 1/4 a cup difference or so.. I LOVE the amount of chocolate in this recipe but I would like it a little sweeter. What do all of you scientific bakers out there think?

Thank you in advance for your help!!