Step 1

In a 12-inch skillet over medium, melt the butter. Add the semolina, coconut and cornmeal, then cook, stirring often, until the mixture begins to brown, 4 to 5 minutes. Transfer to a large bowl and cool until barely warm to the touch, about 30 minutes.

Step 2

Meanwhile, in a medium saucepan, combine 214 grams (1 cup) of the sugar, the honey, lemon zest, ¼ teaspoon salt and ½ cup water. Bring to a boil over medium, stirring to dissolve the sugar, then cook until slightly more viscous, about 5 minutes. Transfer to a 2-cup liquid measuring cup or small bowl; you should have about 1¼ cups. Cover and set aside until ready to use.

Step 3

Heat the oven to 350°F with a rack in the middle position. Butter the bottom and sides of a 9-inch square baking pan. To the cooled semolina mixture, whisk in the yogurt, tahini and ½ cup water. Let stand at room temperature for another 30 minutes to hydrate.

Step 4

In a small bowl, whisk together the remaining 107 grams (½ cup) sugar, the remaining 1/2 teaspoon salt, the baking soda and baking powder. Whisk the mixture into the semolina-yogurt mixture. Transfer to the prepared pan and spread into an even layer. Sprinkle the sesame seeds evenly over the surface and bake until golden brown, 35 to 40 minutes. Cool on a wire rack for 10 minutes.

Step 5

Remove and discard the lemon zest from the syrup, then stir in the lemon juice and orange flower water (if using). With a toothpick, poke holes in the warm cake at 1-inch intervals. Slowly and evenly pour on the syrup. Let stand for 2 hours. To serve, cut into pieces directly in the pan.