In a large bowl, whisk together the dry ingredients (flour, cinnamon, ginger, salt and baking soda).
Add the wet ingredients (eggs, sugar, buttermilk, applesauce and oil) to the flour mixture, and whisk gently until combined.
Use a rubber spatula to pour batter into the prepared pan.
Bake until the cake is just barely firm to the touch, toothpick inserted into the center of the cake comes out clean, and the edges of the cake begin to pull away from the pan -- about 55 minutes.
Let the cake cool on a wire rack, then use a dinner knife to loosen the sides and invert the cake onto the rack.
Remove the parchment paper. Wrap tightly in plastic wrap and place in freezer for at least 30 minutes to make slicing easier.
For the frosting
In the bowl of an electric mixer, using the paddle attachment, cream together the cream cheese and powdered sugar at medium speed until smooth.
Pour in the heavy cream and almond extract and beat to combine.
Switch to the whip attachment and whisk at high speed until very think, with a consistency like a mousse.
To assemble:
Use a serrated knife to trim the top of the cake and cut it in half.
Place the top half on your cake card. Cover the top with a thick layer of frosting.
Top with the second half of the cake. Spread a thin layer of icing on the cake (crumb coat) and then chill another 30 minutes in the refrigerator to set.
Ice the cake, making the sides and top as neat as possible (use an offset spatula or a rubber dough scraper, leaving a half cup of frosting to decorate the top of the cake.
Use a bench scraper to gently press the finely chopped walnuts into the sides of the cake.
Put a small star piping tip in a disposable piping bag and trim off the bottom of the bag. Use a rubber spatula to scoop the remaining frosting into the piping bag. Pipe 8 small rosettes at evenly space intervals around the edge of the cake and top each with a walnut half.
Notes
This is the perfect cake for a fall party - it freezes unfrosted extremely well. It can be defrosted overnight in the refrigerator and iced and decorated the day of a party.