Step 1

FOR THE PASTRY: Adjust oven rack to middle position and heat oven to 400 degrees. Line rimmed baking sheet with parchment paper. Pulse flour, sugar, and salt in food processor until combined, about 3 pulses. Add butter and pulse until mixture resembles coarse meal, about 10 pulses. Add ½ cup water and pulse until mixture forms dough, about 10 pulses.

Step 2

Transfer half of dough (11 ounces) to lightly floured counter, knead briefly until dough comes together, and roll into two 12-inch ropes. Transfer ropes to prepared baking sheet. Press ropes with hand into 12 by 3-inch rectangles. Cover with plastic wrap and refrigerate until ready to use.

Step 3

Meanwhile, lightly beat eggs and almond extract in 2-cup liquid measuring cup. Bring remaining 1 cup water to boil in medium saucepan over high heat. Add remaining dough to boiling water and cook, stirring constantly, until ball forms, about 2 minutes. Reduce heat to low and cook, stirring constantly, until mixture is uniformly shiny and pulls away from sides of pan, 3 to 5 minutes.

Step 4

Transfer hot dough to food processor and process for 10 seconds. With processor running, slowly add egg mixture until incorporated, scraping down sides of bowl as needed. Divide warm dough mixture between chilled dough rectangles. Spread evenly.

Step 5

Set baking sheet with pastry inside second rimmed baking sheet. Bake for 15 minutes, then reduce oven temperature to 350 and bake until pastry is puffed and golden brown, about 75 minutes longer. Turn oven off and, using paring knife, make four ½-inch horizontal slits in each long side of both pastries. Prop open oven door with wooden spoon. Leave pastries in turned-off oven for 20 minutes. Remove from oven and let cool completely on baking sheet, about 1 hour.

Step 6

FOR THE GLAZE: Whisk sugar, milk, salt, and almond extract together in bowl until smooth. Slowly whisk in butter until incorporated. Drizzle glaze over each pastry and top with toasted almonds. Serve.