Preheat the oven to 350°F (175°C). Line 2 baking sheets with parchment paper.

Whisk together the all-purpose flour, fine semolina, powdered sugar, baking powder, mahlab, and ground cardamom in a large mixing bowl.

Rub 1 cup (227 g) unsalted butter into the dry ingredients until the mixture resembles damp sand.

Pour in 1/2 cup (120 ml) whole milk. Mix until a soft, cohesive dough forms.

Cover the dough and rest it for 20 minutes at room temperature.

Combine the date paste, 2 tablespoons (28 g) unsalted butter for filling, ground cinnamon, and chopped walnuts in the second bowl.

Divide the date filling into 24 small balls, using about 2 teaspoons of filling per ball.

Divide the rested dough into 24 equal portions. Flatten each portion into a small disc in your palm.

Place 1 date filling ball in the center of each dough disc. Enclose the filling and roll the dough into a smooth ball.

Press each filled ball gently into the maamoul mold. Tap the mold firmly to release the shaped cookie.

Arrange the shaped cookies 1 inch apart on the lined baking sheets. Bake until the bottoms are lightly golden but the tops remain pale.

Cool the maamoul on the baking sheets for 10 minutes. Transfer the cookies to a wire cooling rack to cool completely.