Biology: Graham Cracker Toffee Lab Snack

Courtesy of Jennifer Wolff

“Lab snacks” are a longstanding tradition in the biology department. Sharing a snack gives us a chance to take a break, get out of the lab, and get to know each other a bit during our four-hour lab sessions. While our most traditional and popular lab snack seems to be chips and salsa, this one has also been a perennial favorite with my students. 


  • 2 sticks salted butter 
  • 1 cup brown sugar 15 graham crackers (full rectangles) 
  • 12 ounces semi-sweet chocolate chips 
  • ½ cup chopped almonds or pecans (optional)


Line a cookie sheet that has sides with foil or a baking mat. Arrange graham crackers to cover the whole area (break crackers to fit if necessary). Melt butter in saucepan. Add brown sugar and stir until sugar dissolves. Be patient and keep stirring until it’s really incorporated, then simmer for 2 minutes. Pour mixture over grahams and spread it evenly. Bake at 400 degrees for about 6 minutes. Observe closely so it doesn’t burn – it will get bubbly. Remove from oven and sprinkle chocolate chips evenly on top and let sit for about 2 minutes until chocolate is melty. Remove from oven and spread melted chocolate evenly over top. Place in freezer (or outside in winter!) for 20 minutes (or in refrigerator for a little longer). Break into pieces and store in airtight container.