In a large saucepan, combine the apples, brown sugar, lemon juice and apple pie spice. Cook over medium-high heat for 5 minutes or until syrup is thickened and apples are tender, stirring occasionally.
In a small bowl, cream butter and sugar. Beat in egg and vanilla. Combine flour, baking soda and salt; add to creamed mixture alternately with buttermilk. Spoon batter into a greased 9-in. springform pan. Arrange apple mixture over top; sprinkle with almonds.
Bake at 350° for 20-25 minutes or until a toothpick inserted in the center comes out clean. Cool on wire rack. Remove sides of pan. Combine glaze ingredients; drizzle over top.