Step 1

Preheat oven to 350°F. Lightly coat a 9"-diameter cake pan with nonstick spray; line bottom with a parchment paper round. Lightly coat parchment with nonstick spray. Mix cardamom and 2 Tbsp. sugar in a small bowl; set aside.

Step 2

Whisk flour, baking powder, 1 cup sugar, and 1/2 tsp. salt in a large bowl. Make a well in the center; add eggs, yogurt, oil, and citrus zest and whisk to combine. Switch to a wooden spoon or rubber spatula and gradually work in dry ingredients, mixing until smooth. Fold in berries; scrape batter into prepared pan.

Step 3

Mix tahini, a pinch of salt, and remaining 2 Tbsp. sugar in another small bowl. Drizzle evenly over batter; sprinkle reserved cardamom sugar over top.

Step 4

Bake cake until a tester inserted into the center comes out clean, 50–60 minutes. Transfer to a wire rack; let cool in pan. Invert onto a plate, then turn right side up.

Step 5

Cake can be baked 2 days ahead. Store tightly covered at room temperature.