What a great way to immortalize somesone! The recipe is wonderful, but I would top it with something homemade and use a 9x12 baking pan. Also, the last time I used Heidi's version, it required less baking time. Test with a toothpick for dryness after 30 minutes. Perhaps in an 8" pan it takes more time.
Hersheys has an easy frosting recipe:
1 stick butter, 2/3 c. cocoa, 3 c. powdered sugar, 1/3 c. milk and 1 tsp. vanilla. Melt butter, stir in cocoa and alternated sugar and mild to desired consistency. Add more milk if necessary.