Grease the cake pans sides and bottoms and line bottoms with parchment paper, dust lightly with flour. Whisk flour, baking powder, baking soda,cinnamon, ginger, nutmeg and salt in large bowl.
Using electric mixer, beat butter in another large bowl until smooth. Beat in brown sugar. Add eggs 1 at a time, beating to blend between additions. Beat in pumpkin.
Add dry ingredients to butter mixture in 3 additions alternately with milk in 2 additions, beating to blend between additions.
Divide batter between pans.
Bake cakes until toothpick inserted into center comes out clean, about 40 minutes.
Cool in pans on rack 15 minutes. Run knife around cakes to loosen. Invert cakes onto racks. Remove parchment. Using tart pan bottom as aid, turn cakes over onto racks, top sides up, and cool completely.
Once completely cooled, using a very sharp long knife, cut each cake layer in half.
* Note: The cakes can be made the day ahead, wrapped in plastic and stored at room temperature. Save icing them until the morning of the dinner.

Cream Cheese Filling

In the bowl of an electric stand mixer fitted with the paddle attachment, beat the cream cheese on medium-high speed until smooth and creamy.
Add the butter; beat until smooth and fluffy, 2 to 3 minutes. Add the sifted confectioners’ sugar, ½ cup at-a-time, beating well after each addition, scraping sides and bottom of bowl as needed. Add the vanilla, mix to combine. If piping the frosting, refrigerate frosting for 15 to 20 minutes before assembling cakes (frosting will firm up, making it much easier to pipe).
*Frosting can be refrigerated overnight, but allow frosting to come to room temperature and beat on low speed in the bowl of an electric stand mixer fitted with the paddle attachment until smoo

Assemble the Cake

Trim rounded tops from cakes. Using long serrated knife, cut each cake horizontally in half.
Place 1 cake layer, cut side up, on large platter.
Separate the cream cheese filling into 3 equal amounts.
Spoon or pipe the filling on the first layer of cake, spreading to edges so when you assemble the cake you will see nice layers of filling at the edges of the cake.
Repeat 2 more times top with remaining cake layer, cut side down.
Put a large dollop of Caramel sauce on the top, and sprinkle the toasted chopped nuts. OMG!