Preheat oven to 350°F. Grease a 10x15 inch baking pan.
In a bowl, add 1/2 cup sour cream. If you don't have sour cream on hand, you may replace with 1/2 cup yogurt and 1/2 tsp baking soda.
Add 2 eggs.
Measure 1 cup stick of butter.
In a saucepan, melt together butter, 1 cup water, and 5 tbsp cocoa powder. Keep on low heat and let it boil.
After your mixture has melted, turn off the heat and let it cool a bit.
Add 2 cups of flour to your egg and sour cream mixture.
Add 1.5 cups sugar.
Add 1 tsp of baking soda.
Add 1/2 tsp salt.
Mix together. You may mix by hand or with an electric beater. It should be as thick as cookie dough at this point:
Slowly add your chocolate mixture to your dough, and start beating your batter. Again, you may feel an electric beater may be of better help. Should look like chocolate cake batter.
Pour into your greased baking dish, and place in your oven, baking for 20 min.
Toward the last 10 minutes of baking, start your chocolate sauce. Similar to the process we did earlier. Melt together your 1/2 cup stick butter, 6 tbsp milk, and 5 tbsp cocoa.
Once your mixture has become glossy, turn off heat. Add your powdered sugar. You may want to sift your powdered sugar to prevent lumps. Otherwise blend well.
Your cake should be done. While your cake is still warm, pour your sauce over your cake.
Now you may enjoy it right away, or I like to refrigerate for a couple hours to harden. Top with walnuts or shaved coconut. It's up to you! Enjoy!