1Heat oven to 350°F (or 325°F if using dark or nonstick pan). Spray 9-inch springform pan with cooking spray. In food processor or blender, place 1 cup almonds; cover and process until almonds are finely ground. In large bowl, beat almonds and remaining cake ingredients except marmalade with electric mixer on low speed 30 seconds, scraping bowl constantly. Beat on high speed 3 minutes, scraping bowl occasionally. Pour batter into pan.
2Bake 45 to 55 minutes or until top is evenly dark golden brown and cake springs back when touched lightly in center.
3Cool in pan 10 minutes. Remove side of pan. Spread marmalade over top of cake. Cool completely, about 1 hour.
4In chilled small bowl, beat whipping cream and 2 tablespoons sugar on high speed until soft peaks form. Spoon or pipe whipped cream around edge of cake; sprinkle 1/3 cup almonds over whipped cream. Refrigerate until serving. Garnish with orange twist.