In a large mixing bowl, bring cheddar cheese, Swiss cheese, and cream cheese to room temperature. Add sour cream, horseradish mustard, and onion powder. Beat with an electric mixer on medium speed until combined and mixture is slightly fluffy.

Line one 7-1/2x3-1/2x2-inch or two 5-1/2x3x2-inch loaf pan(s) with plastic wrap. Sprinkle one-fourth of the nuts in the large pan or one-eighth of the nuts in each of the smaller pans. Spread one-fourth of the cheese mixture over nut layer (one-eighth in each of the smaller pans). Continue layering cheese and nuts, pressing into pan(s) to make 4 even layers of each nuts and cheese. Cover and chill in the refrigerator for at least 2 or up to 8 hours.

To serve, unmold onto serving plate or tray; let stand 10 minutes before serving. Serve with pumpernickel or sourdough bread toast rounds. Garnish the platter with a selection of small sausages, cocktail onions, and pickles, if desired. Makes 20 appetizer servings.

Prepare as above. Cover and chill in the refrigerator for up to 24 hours. Unmold and serve as above.