Heat brown sugar and 1/4 cup butter in a small saucepan until bubbly
pour into bottom of a nonstick 9 inch cake pan. Place pineapple rings
in a single layer snugly in bottom of pan ontop of brown sugar mixture.
Scatter chopped pecans over, if desired.
Combine flours, ground almonds, baking powder and salt. In a bowl
of standing mixer combine butter and sugar and cream on low speed
using paddle attachment. Add eggs, one at a time, stirring after each
addition. Add vanilla. Fold in 1/2 of the dry ingredients and 1/2 of the sour cream. Stir
to combine, add remaining dry ingredients and sour cream. Stir to blend. Spoon
batter into prepared pan and smooth top. Bake in preheated 325 F oven for 1 hour, check
after 45 mins. A toothpick inserted into center of cake should come out clean. Let cool
on a wire rack for 10-15 mins. Invert on to a desert platter. Add cherries into holes
in pineapple rings, if desired. Serve warm or at room temp.