Step 1

Preheat the oven to 375 degrees F.

Step 2

Place two ounces of the chocolate chips in a microwave-proof bowl.

Step 3

Microwave the chips, one minute at a time, slightly stirring after each minute until the chips are completely melted.

Step 4

Combine the graham cracker crumbs and the melted butter.

Step 5

Into the graham cracker crumb mixture, stir in the walnuts and the remainder of the chocolate chips. Set aside.

Step 6

In a separate bowl, sift the flour with the soda and salt.

Step 7

Add the butter and cream well.

Step 8

Gradually add the sugar; cream well.

Step 9

Add the eggs, one at a time, beating well after each.

Step 10

Blend in the melted chips and the vanilla.

Step 11

At a low speed, add the dry ingredients alternating with the buttermilk. *Begin and end with the dry ingredients.

Step 12

Pour into a 13x9 greased and floured pan.

Step 13

Sprinkle the cake batter with the reserved crumb mixture.

Step 14

Bake 30-40 minutes until a toothpick inserted into the middle of the cake comes out clean.

Step 15

Remove the cake from the oven and let cool completely.

Step 16

In a clean bowl, beat the heavy cream with two tablespoons of sugar until stiff peaks form.

Step 17

Frost the cake.

Step 18

Cover the cake and refrigerate until you are ready to serve.