Pre-heat oven to 375F (190C). Line a cookie sheet with parchment paper.
Roll out the puff pastry and lightly roll to even it out if necessary, then cut the sheet in two equal parts, my sheets measured 10x6 inches (25x15cm) , place them on the prepared cookie sheet and prick very well with the tongs of a fork.
Brush the dough lightly with milk and sprinkle with a little icing sugar. Bake for approximately 15 minutes or until golden. Remove from the oven, and immediately move to a wire rack to cool completely (if the pastry is very puffy lightly flatten with a clean towel).
PASTRY CREAM
In a medium pot, heat over low the milk and cream, do not boil. Remove from heat and let cool to warm.
In a medium pot add the yolks and sugar, whisk together until combined, then add the flour and vanilla, place pot over low/medium heat, slowly add warm milk/cream, whisking continuously until thickened.
Remove the cream to a glass or ceramic bowl, cover with plastic wrap (make sure wrap touches the cream mixture), let sit for 20 minutes then refrigerate at least 1-2 hours.
PUTTING IT TOGETHER
Pour 1/2 cup of Alkemes (or desired liquid) into a bowl and dip the lady fingers turning a couple of times in the liquid.
On a large square plate or board place one puff pastry strip, spread half the pastry cream on top, top with a layer of Alkemes dipped Lady Fingers. Top with the remaining cream and place the 2nd strip of puff pastry on top.
Refrigerate for at least 1-2 hours or even over night. Sprinkle with powdered sugar before serving. Enjoy!
Notes
If you can't find or would prefer to not use Alkemes you can substitute with strawberry juice, rum, red Campari or your preferred liqueur, cherry or strawberry would work.The cake should be stored in the refrigerator, in an airtight container or wrapped in plastic. It will keep for up to 2-3 days in the fridge.