In a pot on medium heat melt butter; add brown sugar and bring to a boil for 7 minutes, stirring constantly. (Start a timer as soon as you put the brown sugar in). Add whole almonds stirring constantly for another 7 minutes. (Should reach the hard crack stage.) Spread mixture on a greased cookie sheet. Place 2 cups chocolate pieces (I use 1/2 dark and 1/2 light chocolate) on the mixture while it is still hot. Spread chocolate evenly over whole mixture. Sprinkle with 2 cups chopped almonds. Place another cookie sheet on top of the one with the mixture. Be very careful as you should make the sheets fit exactly as you have to hold the two together and flip them so that the mixture goes into the second sheet. Repeat the steps by placing remaining 2 cups of chocolate pieces on the mixture; then the remaining almonds. Chill outside the refrigerator as it cools faster with air circulation. When chilled, break in pieces. Store in refrigerator in air-tight container. Let stand at room temperature for 1/2 hour before serving.