Steps
1. Preheat oven to 350°F (175°C) and grease a 9-inch round cake pan.
2. In a mixing bowl, combine flour, sugar, cocoa powder, baking powder, baking soda, and salt.
3. Add milk, vegetable oil, egg, and vanilla extract to the dry ingredients and mix until well combined.
4. Stir in boiling water until the batter is smooth.
5. Pour the batter into the prepared cake pan and bake for 30-35 minutes.
6. For the frosting, beat butter until creamy, then gradually add powdered sugar and mix until smooth.
7. Stir in vanilla extract and milk until the frosting reaches a spreadable consistency.
8. Once the cake has cooled, frost the layers and enjoy!