Preheat oven to 325 degrees. With Pam, spray bunt pan or 10” cake pan. Combine dry ingredients and set aside.
Using a mixer fitted with a paddle attachment, beat the eggs until frothy, about 3 to 4 minutes then add the oil and orange juice, mix thoroughly. Slowly add the dry ingredients and beat with at low speed until combined.
Remove the bowl from the mixer and fold in apples and walnuts, pour into bunt or cake pan and bake at 325 degrees for 1 hour or until firm on top. Cover with aluminum foil if the top starts to get too brown. Cool on a wire rack for 5 minutes, then invert onto rack and let cool completely.
Notes: This is a very sticky cake, make sure you spray you pan well so that is does not stick to the pan when you try to invert it. It can be made the day before and refrigerated directly in the pan as well for easy removal. Squeeze some Lemon juice on the apples to keep them from getting brown while mixing the batter.
Guava Icing: Mix the ingredients in a small bowl and mix until creamy, spread over top of cake.