- 9-inch square baking pan
- Food processor or recloseable gallon-size plastic bag and heavy rolling pin or saucepan for crushing crackers
- Microwave or small saucepan for melting butter
- Citrus zester
- Citrus reamer
- Fine-mesh sieve for straining lemon juice
- Mixing spoon and rubber spatula
- Hand-held electric mixer
- Small sieve for dusting with confectioners' sugar
For the Crust
- 1-1/2 cups graham cracker crumbs (about 10 whole crackers, crushed)
- 1 stick (8 tablespoons) unsalted butter, melted
For the Filling
- 3 extra-large eggs
- 1/3 cup fresh lemon juice, strained
- 1 cup granulated sugar
- 1 teaspoon baking powder
- About 1/4 cup confectioners' sugar
- Pinch of salt
- Finely grated zest of 2 lemons
- Preheat the oven to 350 degree F with a rack in the center of the oven.
- Place the graham cracker crumbs and the melted butter in a medium mixing bowl. Use a wooden spoon or a rubber spatula to mix them together thoroughly. Scrape the mixture into the baking pan, and use your fingers to press the mixture evenly onto the bottom of the pan. Bake for 10 minutes, then remove the pan from the oven to cool while you make the lemon filling. Keep the oven at temperature setting.
- Break the eggs into a large mixing bowl, then add the granulated sugar. With the mixer on high speed, beat the mixture until it is light yellow and almost doubled in volume, about 3 minutes. Move the beaters around the bowl and scrape down the sides with a rubber spatula several times while mixing. Add the baking powder and salt, and beat on low speed until just mixed, scraping down the sides of the bowl. Beat in the lemon zest and juice.
- Pour and scrape the filling into the crust and smooth the top with a rubber spatula. Bake for 25 minutes, or until the top is golden brown and wiggles only slightly when the pan is moved. Remove the pan from the oven and allow it to cool. Place confectioners' sugar in a small sieve and sprinkle generously over the top of the cooled fining. Cut into 16 squares.
- The squares can be refrigerated, covered securely with plastic wrap, for up to 1 week. To freeze, allow them to cool completely after baking. Do not dust with confectioners' sugar. Spread them on a baking sheet and place in the freezer for at least 3 hours. When the bars are thoroughly frozen, stack them in a plastic bag for up to 3 months. Use a waterproof marker to note the contents of the bag and the date. Defrost them in the bag at room temperature for 1 to 2 hours. Dust with confectioners' sugar before serving.