- With the rack in the middle position, preheat the oven to 180°C (350°F). Generously butter a 25-cm (10-inch) tube cake pan or 2.5-litre (10-cup) novelty (cathedral) cake pan.
- In a bowl, combine the flour, baking powder and salt. Set aside.
- In another bowl, combine the sour cream and applesauce. Set aside.
- In another bowl, cream the butter with the sugar and the oil using an electric mixer. Add the eggs one at a time, beating constantly until smooth and creamy. Add the vanilla.
- With the mixer on low speed, add the dry ingredients, alternating with the sour cream mixture. Using a spatula, gently fold in the chopped nuts.
- Pour the batter into the cake pan. If using a novelty pan, place it on a baking sheet. Bake until a toothpick inserted in the centre comes out clean, about 75 minutes. Let cool partially. Unmould onto a cooling rack and let cool completely. Transfer to a cookie sheet and set aside.
Brown Sugar Glaze
- Place all ingredients except the icing sugar in a saucepan and bring to a boil, stirring to dissolve the sugar. Boil for 1 minute. Remove from the heat and let stand for 10 minutes. Beat with an electric mixer, gradually adding the icing sugar. Add the vanilla. Beat until the mixture thickens but remains thin enough to pour over the cake, 6 to 8 minutes. Pour over the cake immediately, letting the glaze run down the sides. Decorate with nuts.
Can be made a day ahead.