Heat the oven to 350°F with a rack in the middle position.
Mist a 8½-by-4½-inch loaf pan with cooking spray, dust evenly with flour, then tap out the excess.
In a medium bowl, whisk together the flour, baking powder, coriander and salt.
In a large bowl, whisk the eggs, sugar and zest until well combined and lightened in color, about 1 minute.
Add the yogurt and vanilla, then whisk until well combined.
Add the oil and whisk until homogenous.
Add the flour mixture and whisk just until no streaks remain.
The batter will be very fluid.
Spoon 1/2 cup of batter into a smaller bowl.
Stir in raspberry jam.
Spoon most (about 2/3) of the plain batter into the prepared loaf pan, followed by all of the raspberry batter.
Then spread the remaining plain batter on top as best you can and sprinkle evenly with the remaining 2 teaspoons sugar.
Bake until a toothpick inserted at the center of the cake comes out with few crumbs attached, 40 to 45 minutes.
Let the cake cool in the pan on a wire rack for 10 minutes.
Invert the cake onto the rack, lift off the pan and turn the loaf upright.
Cool completely, about 1½ hours, before slicing and serving.