Garnish: 2-3 tbsp. Marcona almonds, coarsely chopped, sprinkle of fleur de sel
Position a rack in the middle of the oven. Preheat to 350 degrees F. Oil an 8 ½ inch springform pan. Line bottom with parchment cut to fit. Do not oil the parchment.
Place a wire mesh strainer over a medium bowl. Add flours, the sugar, baking soda, salt, and baking powder and sift into the bowl. Add 4 tablespoons of the ground almonds and stir with a wire whisk to distribute the ingredients.
Combine the orange juice, oil, zest, vinegar, vanilla and almond extracts in another bowl and whisk until well combined. Pour into the dry mixture and whisk until the batter is smooth.
Pour the batter into the prepared pan. Rotate pan to level the batter and tap it lightly on the counter. Bake 45 minutes, or until the cake is golden brown, the sides have pulled away from the pan and a tester inserted in the center of the cake is clean. The cake will be well risen, but will compact while cooling.
Place the cake pan on a cooling rack. Run a thin knife between the cake and pan. Cool 5 minutes and release the side ring. Sprinkle a tablespoon of ground almonds on the cake. Place the cooling rack on top of the cake and invert. Remove the pan and paper. Expect the bottom to be pale and moist. Sprinkle with 1-2 tablespoons of the ground almonds and cool completely. Scatter chopped Marcona almonds on the cake and sprinkle with salt. Store the cake loosely wrapped at room temperature up to 3 days. Do not wrap in cling film.