1Heat oven to 350ºF. Grease bottom and side of springform pan, 9x2 inches, or round pan, 9x1 1/2 inches, with shortening.
2In medium bowl, beat 1/2 cup sugar, the butter and egg with electric mixer on low speed about 30 seconds or until smooth. Beat in Bisquick. Spread over bottom and 1 inch up side of pan.
3In small bowl, mix yogurt and egg until smooth. Stir in apple; spoon over batter in pan. Mix 1/4 cup sugar and the cinnamon; sprinkle over apple mixture.
4Bake 45 to 50 minutes or until center is set and crust is deep golden brown. Cool 10 minutes; remove side of pan. Serve warm.