Double rack tag

Microwave cake spilling over when cooking. Any help? - adjusting cooking times for microwaves

Recently, I have a microwave cake recipe online. When I baked the cake starts to sputter. The cake was baked in a bowl in the microwave and put on a plate to cover it. What causes this happen and how can I prevent it happening again?

Here is the recipe
INGREDIENTS
• 3 tablespoons butter, softened
• 1 / 4 cup white sugar
• 1 egg
• 1 c. Tea-Vanilla extract
• 1 / 4 cup milk
• 1 / 2 cup all-purpose flour
• 2 tablespoons cocoa powder
• 1 / 4 c. Tea baking powder
• 1 pinch of salt









NOTES
1. Spray a microwave dish with a Teflon cooking spray and set aside. In a mixing bowl, combine butter, sugar, eggs, vanilla and milk. Flour, cocoa powder, baking soda and salt, stir the mixture is smooth. Pour into a greased bowl.
2. Cover and cook on high for 2 to 2 1 / 2 minutes, or until the cake springs back when touched. Since all microwaves cook differentlyAdjusting the cooking time to accommodate