Ingredients

  • 1/3 cup vegetable oil, such as safflower, plus more for pan
  • 1 cup packed light-brown sugar
  • 1 ripe firm pineapple (skin removed), cut into 16 thin wedges and cored (see note, above)
  • 1 cup all-purpose flour (spooned and leveled)
  • 1/2 cup whole-wheat flour (spooned and leveled)
  • 1 1/2 teaspoons baking powder
  • 1/2 teaspoon baking soda
  • 1/2 teaspoon salt
  • 3/4 cup low-fat buttermilk
  • 2 large eggs
  • 1 teaspoon pure vanilla extract

Method

  • 1.Preheat oven to 350 degrees. Brush a 9-inch square baking pan with oil; line with a strip of parchment paper, leaving an overhang on two sides. Brush paper with oil. Sprinkle bottom of pan with 1/4 cup sugar. Trim pineapple wedges to no more than 4 to 5 inches long; arrange in pan in groups of four, alternating direction.
  • 2.In a medium bowl, whisk together flours, baking powder, baking soda, and salt; set aside.
  • 3.In a large bowl, whisk together buttermilk, eggs, vanilla, oil, and remaining 3/4 cup sugar. Add flour mixture; mix just until combined. Pour batter over pineapple. Tap pan firmly on counter to settle batter, then smooth top.
  • 4.Bake until a toothpick inserted in center of cake comes out clean, 50 to 60 minutes. Cool 20 minutes in pan; invert onto a serving platter (peel off and discard paper).