Preheat oven to 350F. Place a parchment round on the bottom of an 8 inch cake pan that is 4 inches tall. Spray the pan, place prepared mix in pan and bake until cake springs back lightly when touched. Let cake cool completely and de-pan.
While the cake is cooling, place sugar, wine, and water in a pan and bring to a boil. Working carefully, peel the pears paying special attention to their natural shape. Once the water has boiled, very gently lower the peeled whole pears into the pan. Cover the top of the fruit with a parchment circle the same size as the pan with a little hole cut in the center. The center hole is important as it allows steam to escape while still covering the fruit and allowing it to all cook at the same rate. Bring the mixture to a boil, reduce heat and simmer for 10 minutes. Place the pan in an ice water bath the stop cooking time. There will be extra pears and syrup!
Preheat oven to 350 degrees F. In a medium bowl combine walnuts, brown sugar, and heavy cream, mix well to combine. Line a sheet tray with parchment and spray with non-stick spray. Bake for 10 minutes, stir, then start stirring every 5 minutes. Remove from oven with coating is dry and slightly crystallized. Let cool completely, break into pieces and store in an air tight container.
Get a heavy bottomed non-reactive pan (like stainless steel or copper) screaming hot, then carefully pour in the sugar. Using a wooden spoon, stir and break up bits of sugar as it melts and gets golden brown. Remove from heat if caramel is getting too dark, continuing to mix and crush until mixture is completely liquid and brown. VERY CAREFULLY add in the cream, swirling as you go- the steam will burn you so take care! Stir in salt and vanilla paste and gently bring back to a boil to cook out any lumps. Place sauce over an ice water bath to cool down.
Place cake on a board and trim the belly. Scoop out cake a half an inch down so that there is a depression for the pears. Dip 4 of the poached pears in vanilla bean caramel. Scatter prepared walnuts around pears and spoon additional sauce on top of pears.