Preheat the oven to 350 degrees F (180 degrees C). Grease an 8x8-inch pan or line with parchment paper on the bottom, leaving a little overhang to easily remove bars.

Stir melted butter, 3 tablespoons sugar, almond extract, and salt together in a bowl. Add flour, and mix until well incorporated. Press dough mixture into the prepared pan in an even layer. 

Bake in the preheated oven until edges start to turn a light brown, 15 to 20 minutes. Remove from the oven, and set aside.

Meanwhile, combine cranberries, 1/4 cup sugar, water, and 1 1/2 tablespoons lemon zest in a small saucepan. Cook over medium heat, stirring often. Once cranberries start to pop, mash down with the back of a spoon, until cranberries break down into a smooth consistency, 9 to 12 minutes. Set aside.

Whisk eggs, 3/4 cup sugar, lemon juice, flour, and 1 tablespoon lemon zest in a bowl until well combined.

To assemble, spread the cranberry mixture evenly over the crust, and pour the lemon layer mixture over the cranberry layer.

Return to the oven and bake until filling is set, 20 to 25 minutes.

Cool completely in the pan, and run a knife around the pan edges. Cut into squares and dust with confectioners sugar right before serving. Store leftovers in an airtight container.