Start by making the caramel topping. Take brown sugar and butter and combine and melt in a saucepan on medium heat until sugar dissolves and the mixture is bubbly, this should take several minutes. (After sugar melts, don’t stir.)
Pour mixture into a 10 inch diameter non-stick cake pan with 2 inch high sides. Arrange pineapple slices in a single layer on top of the caramel mixture.
Preheat oven to 170 ˚C (325 ˚F / gas mark 3).
Whisk the flours, almonds, baking powder, and salt in a large mixing bowl (dry ingredients)
In a separate bowl, use an electric mixer to beat the sugar and butter together until light. Add eggs one at a time, beating after each addition. Beat in the vanilla. Add dry ingredients alternately with sour cream in 2 additions each, beating well after each addition.
Pour cake batter over caramel and pineapple in pan. Bake cake for about 1 hour – 1 hour 15 minutes or until tester inserted into the center comes out clean.
Cool cake in pan on a rack for 10 minutes.
Turn the cake upside down onto a platter.
Serving Size 5 - 7 people