My grandma's Texas sheetcake

I asked my grandma for this recipe to make for a party about a month ago, since it was one I loved as a kid. I don't bake very much and kind of winged the process since she didn't have it written down formally, but it turned out great. That said, any input on making the recipe clearer would be appreciated!

Cake - Ingredients:

• 2 cups flour

• 2 cups sugar

• 1/2 tsp salt

• 1 tsp baking soda

• 1 1/2 tsp cinnamon

• 2 sticks butter

• 1 cup water

• 4 tbsp cocoa powder

• 2 eggs

• 1 tsp vinegar

• 1 tsp vanilla

• 1/2 cup buttermilk

Cake - Directions:

1. In a large bowl, mix flour, sugar, salt, baking soda, and cinnamon.

2. Combine butter, water, and cocoa in a saucepan. Bring to a boil. Remove from heat and add to the dry stuff, mixing until smooth.

3. Beat the eggs. Add the eggs, vinegar, vanilla, and buttermilk, and mix until smooth.

4. Pour evenly into a 13x9 (ish) pan and bake at 375F for 20 minutes. Allow the cake to cool before adding the frosting.

Frosting - Ingredients:

• 1 stick butter

• 4 tbsp cocoa

• 6 tbsp milk

• 1 box powdered sugar (wasn't sure what this meant, I used 2 cups, internet seems to suggest 3-4)

• 1 tsp vanilla

Frosting - Directions:

1. Combine butter, cocoa, and milk in a saucepan and bring to a boil.

2. Pour into a mixing bowl and mix in the vanilla. Gradually mix in the powdered sugar. Spread evenly over cake.

bon appetit