Pre-heat the oven to 350 degrees. Grease and flour a 14-cup bundt pan.
Start my toasting your pecans in the oven for 8 – 10 minutes or until fragrant. Be sure to toss half way through cooking time. Set aside when they are done.
Prepare filling: Beat butter, cream cheese and sugar until light and fluffy. Stir in egg, vanilla and flour and mix until smooth. Set aside.
Prepare cake: In the bowl of an electric mixer fitted with the paddle attachment, beat sugars, canola oil and apple sauce. Add in the eggs, one by one. Stir in vanilla.
In a separate bowl, combine flour, spices, salt and baking soda. Working in batches, add this to your wet mixture.
Remove bowl from mixer and fold in pecans and apples.
Baking: Place 2/3 of the batter into the bundt pan. Spoon in the cream cheese mixture and, using a paring knife, swirl around to incorporate evenly. Be sure to leave about an inch border, so that the cream cheese does not leak out while baking. Place the remaining 1/3 of the batter on top and bake for 60 – 75 minutes until a toothpick comes out clean. Cool completely on a wire rack.
Frosting the cake: Bring brown sugar, butter and milk to a boil in a small saucepan, whisking constantly. Remove from heat and stir in vanilla. Be careful, as mixture will bubble up violently! Gradually whisk in confectioners’ sugar. Allow mixture to harden slightly and pour over completely cooled cake. Garnish with additional pecans, if desired.