Step 1Sift together flour, cinnamon, baking soda, salt and nutmeg. Set aside.
Step 2Beat butter and sugar at medium speed until light and fluffy, 4 minutes. Add eggs, 1 at a time, mixing each well before adding another. Add vanilla; scrape down sides of bowl. Mix in dry ingredients, apples and nuts on low speed. Increase speed to medium and mix 10 seconds more. Transfer to greased 9-inch springform pan and set on baking sheet. Smooth cake top.
Step 3Bake at 350 degrees until toothpick inserted in center comes out clean, about 45 minutes to 1 hour. Cool completely on rack. Use small sharp knife to separate cake from sides of springform; remove ring. Serve warm (gently reheat in 300-degree oven for about 10 minutes). Cut into wedges; serve with a dollop of ice cream and warm caramel sauce.