Named for its ease of assembly, lemon ice box pie can be chilled in the refrigerator until the creamy lemon filling sets. Despite the name, however, many lemon ice box pie recipes call for baking to ensure a firm-set filling before placing the pie in the icebox to chill. The result with either method is similar to the difference between baked and no-bake cheesecake -- nearly identical flavor with a slightly firmer texture when baked.
Lemon ice box pie calls for a sweet cookie crust that doesn't overpower the light citrus flavor in the filling. Graham crackers, shortbread cookies and vanilla wafer cookies are all suitable candidates for lemon icebox pie crust. Pulse the cookies or graham crackers in a food processor to a fine texture. If the cookies lack sweetness, add granulated or powdered sugar to taste. Add lemon zest or ground lemon candies to infuse the crumbs with lemon flavor. Mix melted butter with the crumbs to make a crumbly dough-like mixture. Press the crumb mixture firmly into a baking pan -- opinions vary on whether a pie pan or spring-form cheesecake pan is best.
Lemon ice box pie must be baked to set the filling if egg yolks are used along with sweetened condensed milk and lemon juice. The egg yolks bind the ingredients, making a firmer filling with more of a custard-like texture. The exact ratio of ingredients varies among recipes. For two standard 14-ounce cans of sweetened condensed milk, similar results are achieved when you use 1 cup of lemon juice and 6 egg yolks, or only 2 egg yolks and 2 cups of lemon juice. Test various ratios to find your preference. Beat the ingredients with an electric mixture and pour it into the pie shell. Bake at 350 degrees Fahrenheit for 15 to 20 minutes or until the filling partially set. Cool the pie at room temperature. Cover and refrigerate for about 6 hours or overnight before serving.
The no-bake version is filled with only sweetened condensed milk and lemon juice. It takes about two cans of sweetened condensed milk and 3/4 to 1 cup of lemon juice to make enough filling to fill a standard 9-inch pie crust. Adjust the amount of lemon juice to suit your taste preference. Mix the ingredients well with an electric mixer until it begins to thicken slightly. Pour the mixture into the graham cracker or cookie pie crust and cover with plastic wrap. A minimum of 6 hours of refrigeration is needed to set the filling, but overnight refrigeration is best.
A dollop of whipped cream adds the finishing touch to each slice of lemon ice box pie. Canned whipped cream or non-dairy whipped topping are sufficient if time is a concern, but these are no substitute for fresh whipped cream. Add powdered sugar and vanilla extract to heavy whipping cream. For every 1 cup of whipping cream, add about 2 tablespoons of powdered sugar and 1/2 teaspoon of vanilla, adjusting the ingredients to suit your taste. Beat the ingredients until firm peaks form. Slice the lemon icebox pie into equal portions. Top each piece with a fresh lemon slice garnish or a lemon twist cut from the lemon peel. Add a dollop of the whipped cream on top of the pie or on the side.