For the syrup:
2 cups granulated sugar
1 cup water
1 tablespoon freshly squeezed lemon juice
1 1/4 teaspoons lavender extract
For the namoora:
3 cups semolina flour
3/4 cup (12 tablespoons) unsalted butter, melted, plus more for coating the pan
3/4 cup granulated sugar
1 cup plain whole-milk yogurt
1 1/4 teaspoons baking powder
1/2 cup whole blanched almonds
Make the syrup: Combine the sugar and water in a small saucepan. Bring to a boil, stirring until the sugar is dissolved. Reduce the heat to a simmer, add the lemon juice and lavender, and stir to combine. Simmer until thickened into a syrup. Remove from the heat and set aside to cool.
Make the namoora: Arrange a rack in the middle of the oven and heat to 400°F. Coat a 9x13-inch baking dish with butter.
Place the semolina, 3/4 cup melted butter, and sugar in a large bowl and stir until well-combined; set aside.
Place the yogurt and baking soda in a medium bowl and stir to combine. Set aside until the mixture has nearly doubled in size.
Pour the yogurt mixture over the semolina mixture and mix well to combine. Transfer to the baking dish and press into an even layer.
Using a butter knife, score the surface of the namoora on the diagonal into approximately 28 diamond-shaped pieces (like baklava). Top each diamond with an almond. Bake until golden-brown, 35 to 40 minutes.
Remove the dish to a wire rack. Drizzle the cooled syrup over the top of the hot namoora. Let cool to room temperature before re-cutting along the scored lines and serving.