Preheat the oven to 350 degrees F. Line two 8" round pans with wax or parchment paper and spray with non stick spray (I like to spray the pan before putting the wax paper in to get it to stick, and then spray the wax paper) -- this helps the cake comes out really easily.
In a large bowl, combine canola oil, eggs, pumpkin, vanilla and brown sugar with a whisk until smooth.
To the bowl add flours, baking soda, salt, cinnamon, nutmeg, and cloves. Stir with a whisk slowly until just combined. Batter will be thick.
Divide batter between the two pans. Bake for 20 minutes or until a toothpick inserted in the center comes out clean. Cool to room temperature.
Assembly*Optional: if you don't want the tops of the cakes to be rounded, you can slice the top off to flatten it.
Spread both cake layers with a layer of the caramel. Place one cake layer on your cake plate, sprinkle with half toasted pecans and spread half whipped cream on top of the dulce de leche.
Place second cake layer on top of the whipped cream. Spread remaining whipped cream on top of the caramel on the second layer, and top with remaining pecans and sprinkle with toffee bits.
Keep covered and refrigerated until ready to serve. You can also freeze for up to 1-2 months!