Preheat oven to 350º. Spray a 9x9 pan with nonstick baking spray with flour.
Beat butter and sugar with an electric mixer until creamy. Add eggs, one at a time, beating well after each addition. Stir in vanilla.
In a medium bowl, combine flour, baking powder, cinnamon, baking soda, and salt. Gradually add to batter mixture, alternately with buttermilk, beginning and ending with flour mixture, beating until combined. Spoon batter into prepared pan, and bake for 22-25 minutes or until a wooden pick inserted in center comes out clean. Pour hot caramel glaze over hot cake; sprinkle with cashews.
1 cup heavy whipping cream
1/2 cup firmly packed brown sugar
1 tablespoon light corn syrup
1 teaspoon vanilla
Combine cream, brown sugar, and corn syrup in pan, Bring to a boil over medium high heat, and boil until mixture reaches 212º on a candy thermometer. Remove from heat, and stir in vanilla. Pour over cake while hot.