Peanut Butter Fudge

I made peanut butter fudge last night. Didn't quite all turn out...the chocolate on the top separated...so one side of the fudge the part that is supposed to be chocolate is clear (probably pure butter!). Anyways I followed the directions exactally, but it was microwave fudge and it didn't say anything about power level and I know our microwave has a good wattage or whatever so maybe it should have been in less time in our microwave. Or it could have been that 1 can of condensed milk isn't 14oz and I only had one can.

Here is the recipe - I got it online from London Mom's forum

Microwave Peanut Butter & Chocolate Fudge

1 [12 oz] pkg. Peanut Butter Chips
1 [14 oz] can Condensed Milk
1/4 cup Margarine
1 cup Semi-Sweet Chocolate Chips

Cook peanut butter chips, 1 cup condensed milk & 2 tbs margarine in
microwave for 7 minutes, stir every 2 minutes.
Spread mixture into wax paper lined, 8" square pan.
Cook chocolate chips, remaining condensed milk & margarine in
microwave for 7 minutes, stirring every 2 minutes.
Spread chocolate mixture on top of peanut butter mixture.
Chill 2 hours or until firm. Cut into squares.

I am eating a piece right now that looks good - and it tastes pretty good too.