In a small bowl, dissolve the sugar and yeast in warm milk. Let it sit for about 10 minutes until frothy.
In a large mixing bowl, combine the flour and salt. Cut in the softened butter until the mixture resembles coarse crumbs.
Add the sour cream, egg, and the yeast mixture to the flour mixture. Mix until a dough forms.
Turn the dough out onto a lightly floured surface and knead for about 10 minutes until smooth and elastic. Place the dough in a greased bowl, cover with a damp cloth, and let it rise in a warm place for about 1 hour, or until doubled in size.
In a medium bowl, combine the ground almonds or walnuts, granulated sugar, and ground cardamom. Mix well.
Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.
Punch down the risen dough and divide it into small balls, about the size of a walnut.
Roll each dough ball into a thin circle, about 3 inches in diameter.
Place a teaspoon of the filling in the center of each dough circle. Fold the dough over the filling to create a half-moon shape. Press the edges together to seal, then use a fork to crimp the edges for a decorative finish.
Use a knife or a special tool to create traditional patterns on the surface of each Shekerbura.
Place the shaped Shekerbura on the prepared baking sheet. Bake in the preheated oven for about 20-25 minutes, or until they are lightly golden.
Allow the Shekerbura to cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely. Serve at room temperature.
Enjoy your meal!