Carefully open each puff pastry sheet. Cut each sheet of pastry at creaes, forming 3 strips. Cut each strip width wise into 7 pieces. Combine egg and 1/4 cup milk; lightly brush egg mixtrure over pastry. Sprinkle with sugar. Place on lightly greased baking sheets. Bake at 400 for 10 to 12 minutes or until golden brown. Move to wire racks to cool. Split into top and bottom halves.
In a saucepan, combine the flour and milk until smooth. Bring to a boil over medium heat; cook and stir for 1 minute or until thickened. Cool. Transfer to a mixing bowl, beat in the butter, sugar, vanilla, almond extract and salt until light and fluffy, about 10 minutes. Spread 1 tablespoon full on bottom half of each pastry, replace tops. You can easily make this a day in advance and store in fridge - when taking out, give about half and hour to warm up.