Grease 8" round cake pan. Line bottom with wax or parchment paper.
Cream butter until fluffy, but not too much. Mix in both types of sugar, then both flours with electric beater until dough is crumbly and clumps together when pressed. Spread evenly in prepared pan and pat down lightly.
Bake in preheated 352F oven 45 minutes.
Remove from oven, and with sharp knife or fork, score into 12 wedges, cutting about 3/4 way through dough. Score with a fork in decorative patterns.
Return to oven; bake about 15 minutes longer or until just lightly golden at edges.
Cool in pan on rack 30 minutes. Loosen sides. Turn out and invert.
Cool completely.
