Preheat oven to 375°F. Line a baking sheet with parchment paper and lightly coat with cooking spray; set aside.

Combine flour, baking powder, cinnamon, nutmeg, and salt in a medium mixing bowl; mix well.

Add yogurt and raisins; stir until combined and small crumbles form.

Turn out dough onto a lightly floured surface; knead 10 times. If dough is sticky, add a little more flour and knead again.

Press dough into a rectangular disk; divide evenly into 8 pieces. Roll each piece into a ball.

Arrange balls on prepared baking sheet so they are close but do not touch.

Brush each ball with egg white. Bake for 22 to 25 minutes, until golden brown. Set aside to cool for 15 minutes before frosting.

To make frosting, combine powdered sugar and water in a small bowl; mix well. Drizzle frosting onto each bun in the shape of a cross.