Texas Sheet cake brownies

So I stole this recipe from the Better Home's and Garden's cookbook, but I made it last night for a potluck, changed it a bit, and it turned out nicely. Hope you enjoy.

Prep time: 25 min
Cook time: 25 min

Cool time 1 hour

Combine these in a medium sized bowl until mixed:

2c. flour

2c. sugar

1 tsp. baking soda
1/4 tsp. salt

1tsp ground cinnamon

In medium saucepan combine and bring to boil (stirring constantly)the following:

1c. butter

1/3c. unsweetened cocoa powder
1c. water

Add boiled mixture to the dry ingredients and mixon medium speed

until thoroughly mixed. Then add:
2 eggs

1/2 c milk

1/2 Tbsp Lemon juice OR vinegar

1 1/2 tsp vanilla

Pour in greased cookie sheet (15X10X1inch) and bake at 350 for 25 minutes

While baking make frosting by heating to a boil:

1/2c butter

6 Tbsp unsweetened cocoa

3 tbsp milk

after bringing to boil, mix in by electric hand mixer:

4 1/2 c powdered sugar

1 tsp vanilla

Pour warm frosting over warm cake and spread and let cool 1 hour.

You can add almonds, walnuts, or pecans if desired.