Tres Leches Cake

For cake:

• 1 box moist yellow cake mix (plus ingredients to make cake)

For milk mixture:

• 1 cup heavy cream
• 14 ounces sweetened condensed milk
• 12 ounces evaporated milk

For whipped cream:

• 1 cup heavy cream or heavy whipping cream
• ½ cup powdered sugar
• ½ teaspoon vanilla