Preheat the oven to 300°F (149°C).
Spread pecans onto a lined baking pan. Toast for 8 minutes.
Remove from the oven. Turn the oven up to 350°F (177°C), then grease and lightly flour three 9-inch cake pans.
Whisk the flour, baking soda, cinnamon, allspice, and salt together in a large bowl.
Whisk the rest of the cake ingredients in a medium bowl.
Pour wet ingredients into dry ingredients and whisk until completely combined.
Fold in 1 and 1/2 cups of toasted pecans. (Save the rest for garnish.)
Spread batter evenly between the 3 prepared cake pans.
Bake for 26-29 minutes or until a toothpick inserted in the center comes out clean.
Rotate pans halfway through baking.
Remove cakes from the oven and allow them to cool completely in the pans set on a wire rack.
Once completely cooled, remove cakes from the pan and level the tops off so they are flat.
I simply use a serrated knife. Discard the tops.
Make the frosting: In a large bowl using a handheld or stand mixer fitted with a paddle or whisk attachment beat the cream cheese and butter together on high speed until smooth and creamy.
Add confectioners’ sugar, vanilla, milk, and salt.
Beat on low speed for 30 seconds, then switch to high speed and beat for 2 minutes. Taste. Add more salt if needed.