1. Preheat oven to 350 degrees F (180 degrees C).
2. In a large bowl, beat eggs and sugar (using an electric mixer).
3. Add vanilla extract. In a separate bowl, combine flour, baking powder and salt. Gradually add to the egg mixture.
4. In a small saucepan, heat milk and butter until hot and butter is melted.
5. Gradually add milk to the batter, whisking until the mixture is smooth.
6. Pour the batter into 9-inch round cake pan and bake in the preheated oven for about 30-35 minutes, or until a toothpick inserted in the center comes out clean.
7. Combine cinnamon and sugar. Sprinkle the top of the cake with the mixture.