Heat oven to 350°F (325°F for dark or nonstick pan). Place cake mix in medium bowl. Using pastry blender (or pulling 2 table knives through mixture in opposite directions), cut in 1/2 cup butter until crumbly. Press firmly in ungreased 13x9-inch pan. Bake 12 to 14 minutes or until set.
In large bowl, beat eggs, corn syrup and 1/4 cup melted butter with whisk until smooth. Stir in almonds and chocolate. Pour over crust.
Bake 28 to 34 minutes longer or until golden brown and set. Cool 30 minutes. Refrigerate about 1 hour or until chocolate is firm. For bars, cut into 8 rows by 6 rows. Store covered in refrigerator.