Prepare the Crust: In a mixing bowl, combine flour and butter until crumbly. Add water and mix until a dough forms. Press into two 12x3-inch strips on an ungreased baking sheet.
Make the Choux Pastry Layer: In a saucepan, bring water and butter to a boil. Remove from heat and stir in flour until a smooth dough forms. Let cool slightly, then beat in eggs one at a time until the mixture is smooth and glossy. Stir in powdered sugar and almond extract.
Assemble and Bake: Spread the choux pastry evenly over the crust. Bake at 350°F (175°C) for about 1 hour or until golden brown. Let cool completely.
Make the Frosting: Whisk together powdered sugar, softened butter, almond extract, and milk until smooth. Adjust consistency as needed.
Glaze and Serve: Drizzle the frosting over the cooled pastry. Let set before slicing and serving.