Coat bottom of a 9-inch round cake pan with melted margarine.
Sprinkle brown sugar over margarine.
Place 1 cherry in center of pan; arrange remaining cherries around edge of pan.
Combine nectarines and lemon juice; toss well. Arrange nectarine slices spokelike, working from center cherry to edge of cherries.
Lightly spoon flour into a dry measuring cup; level with a knife.
Combine flour, almonds, baking powder, baking soda, and salt in a bowl. Beat 2/3 cup granulated sugar and 1/4 cup margarine at medium speed of a mixer until well-blended.
Add extracts and egg; beat well.
Add flour mixture to creamed mixture alternately with buttermilk, beginning and ending with flour mixture; beat well after each addition. Slowly pour batter over fruit.
Bake at 350 for 45 minutes or until a wooden pick inserted in center comes out clean. Cool in pan 5 minutes on a wire rack. Loosen cake from sides of pan using a narrow metal spatula. Invert onto a cake plate; cut into wedges.