Step #1 Preheat oven to 350°F
Spray three 9-inch-diameter cake pans with 1 1/2-inch-high sides with nonstick spray.
Step #2 Combine cake mix, 3 tbsps amaretto, oil, 1 1/3 c water, eggs, & 1/2 tsp almond extract in large bowl; whisk until well mixed.
Step #3 Mix in 1 c chocolate chips.
Step #4 Divide batter among prepared pans.
Step #5 Bake cakes until tester inserted into center comes out clean, about 15 mins.
Step #6 Cool cakes in pans 10 mins.
Step #7 Run knife around pan sides.
Step #8 Turn cakes out onto racks; cool completely.
Step #9 Brush each cake layer with 2 tbsps amaretto.
Step #10 Combine butter & cream in medium saucepan.
Step #11 Stir over medium-low heat until butter melts & mixture comes to simmer.
Step #12 Remove from heat.
Step #13 Add remaining 2 c chocolate chips & whisk until melted.
Step #14 Mix in remaining 3 tbsps amaretto.
Step #15 Cool until barely lukewarm, about 5 mins.
Step #16 Whisk in sour cream & remaining 1/4 tsp almond extract, then powdered sugar.
Step #17 Refrigerate frosting just until thick enough to spread, whisking every once in awhile, about 10 mins.
Step #18 Place 1 cake layer on platter; spread 1/3 c frosting over; top this with second cake layer; spread 1/3 c frosting over; top this with third cake layer; spread remaining frosting over top & sides of cake.
Step #19 Press nuts around bottom 2 inches of cake.
Step #20 Chill 2 hrs.
Step #21 (Can be made 2 days ahead.
Step #22 Cover up with cake dome; keep chilled.
Step #23 )
**Cook time does not include cooling time or chill time.