Preheat oven to 350°F Drain pineapple slices, reserving 2 tablespoons of the syrup. In a very heavy or iron, 10-inch skillet with.
heat-resistant handle, melt butter over medium heat. Add brown sugar, stirring until sugar is melted. Remove from heat.
Arrange 8 pineapple slices on sugar mixture, overlapping slices slightly around edge of pan. Put one slice in center. Fill centers with pecan halves. Halve three remaining pineapple slices. Arrange around inside edge of skillet. Put pecans in centers.
Into medium bowl, sift flour with granulated sugar, baking powder and salt. Add shortening and milk. With electric mixer at high speed, beat 2 minutes, or until mixture is smooth. Add egg and reserved 2 tablespoons pineapple syrup; beat 2 minutes longer.
Gently pour cake batter over pineapple in skillet, spreading evenly, being careful not to disarrange pineapple. On rack in center of oven, bake 40 to 45 minutes, or until golden in color and surface of cake springs back when it's gently pressed with fingertip.
Let skillet stand on wire rack 5 minutes to cool just slightly. With rotary beater, beat cream until stiff. With small spatula, loosen cake from edge of skillet all around. Place serving platter over the cake, and turn upside down; shake gently; lift off skillet.
Serve cake warm, with the whipped cream or ice cream. Note: The pineapple upside-down cake was traditionally baked in an iron skillet. If your skillet does not have an iron or heatproof handle, wrap handle in foil before placing in the oven.