Making the Cake:

1. Preheat Oven: Preheat oven to 350°F (175°C). Grease and flour a 9×13-inch baking pan.
2. Combine Dry Ingredients: In a medium bowl, whisk together flour, baking powder, and salt. Set aside.
3. Cream Butter and Sugar: Beat softened butter and granulated sugar on medium speed until light and fluffy (3-4 minutes).
4. Add Eggs and Vanilla: Add eggs one at a time, beating well after each addition. Mix in vanilla extract.
5. Combine Wet and Dry Ingredients: Alternate adding dry ingredients and milk to the butter mixture, beginning and ending with the dry ingredients. Mix until just combined.
6. Pour Batter: Spread the batter evenly into the prepared pan.
7. Bake: Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean. Cool on a wire rack.

Making the Glaze:

1. Prepare Glaze: In a small saucepan, combine butter, water, and sugar. Cook over medium heat, stirring until butter is melted and sugar is dissolved.
2. Add Vanilla: Remove from heat and stir in vanilla extract.

Glazing the Cake:

1. Poke Holes: Use a skewer or fork to poke holes all over the surface of the warm cake.
2. Pour Glaze: Pour glaze over the cake, allowing it to soak into the holes. Cool completely before serving.