Put curry, paprika, salt and sugar in a small bowl and mix. Put the flour in a big bowl and add in the spice mixture and mix them well.
Add the cubed butter to the flour mixture. Using your fingertips rub them gently until the mixture looks like breadcrumbs.
Add the egg and mix until the dough comes together. Divide the dough in half and cover each with plastic film, flatten the doughs and let them rest in the fridge for 25 minutes. As you divide and flatten the doughs, they rest faster.
Alternatively, if you want to prepare the dough with a mixer: Put curry, paprika, salt and sugar in a small bowl and mix. Put the flour in a big bowl and add in the spice mixture and mix them well. Place the butter in a large bowl and beat on medium speed for 1 to 2 minutes until it is soft with a hand-held mixer or with paddle attachment if using a stand mixer. Add the egg and mix well. Stop the machine and scrape down the sides of the bowl with a rubber spatula to be sure they are all mixed. Add in the flour mixture and mix well until the dough comes together. Divide the dough in half and cover each with plastic film, flatten the doughs and let them rest in the fridge for 25 minutes. As you divide and flatten the doughs, they rest faster.
Remove the doughs from the fridge. Preheat the oven to 350°F(177C°). Line baking sheet with parchment paper or silicone baking mat. Set aside.
Lightly flour the worksurface and the rolling pin, so the dough won't stick. Roll out the dough 9*6 inch(22*15cm)long, ⅕ inch(5mm)thick. Then sprinkle half of the poppy seeds over the dough and use a rolling pin to make them stick. If you have, you can use your cookie cutter or cut them into 1.2 inch (3cm) square pieces with a sharp knife. Repeat the same steps with the other half of the dough.
Bake for 7 minutes until they become firm. Let them cool for 5 minutes on the baking sheet before transferring them to a wire rack to completely cool.