I got this recipe off of one of my mom forums... I wouldn't say they tasted like a Kit Kat bar per se, but they were really good. Especially if you like the sweet/ salty type of treat.
Homemade Kit Kat Bars
60-80 buttery rectangular crackers (I used Saltine crackers)
1 1/2 cups graham cracker crumbs
3/4 cup packed brown sugar
1 cup white sugar
3/4 cup butter
1/3 cup milk
1 cup milk chocolate chips
1 cup semisweet chocolate chips (I used all semisweet chocolate chips, but added about 1 Tablespoon of light corn syrup)
3/4 cup peanut butter
1. Put graham cracker crumbs, brown sugar, white sugar, butter and milk into a saucepan and bring it to a boil. Boil for 5 minutes.
2. Spray pan with oil spray. Put a layer of whole crackers in a 9x13 inch pan and pour 1/2 of the graham cracker crumb mixture over it. Put another layer of crackers and pour the remaining mixture. Add last row of crackers. Note: Press down after each cracker layer.
3. To Make Topping: Melt over low heat the milk chocolate chips, chocolate chips, and peanut butter. Melt at low heat and spread over the top.
4. Cut into thin strips or bars for serving.
Layer the crackers
this is the filling. Make sure to let it boil for the full 5 minutes
Spread 1/2 the filling over the crackers, repeat the layers.
Make sure to press the crackers down so that the filling comes up through the holes.
Melting the chocolate and peanut butter together.