Bring butter, eggs, sour cream, and eggnog to room temperature.

Position oven rack in center of oven and preheat oven to 325°F.

Grease an 8” – 9” fluted tubular shape baking pan (having 5-6 cup capacity), ensuring all crevices are very well greased. Alternatively, spray pan with cooking oil.

In bowl, sift or sieve all-purpose flour, almond flour, custard powder, baking powder, baking soda, salt, and spices together. In small bowl combine the eggnog and rum together. Set dry and wet ingredients aside.

In bowl of stand mixer fitted with paddle attachment, beat the butter at medium speed until silky smooth and pliable. Gradually add the brown and granulated sugars and beat for a couple of minutes, stopping as necessary to scrape sides of bowl. Add the eggs and egg yolk, one at a time, beating well after each addition and scraping down sides of bowl to ensure all ingredients are incorporated. Blend in the vanilla and sour cream until well mixed.

Add the dry and wet ingredients to the batter in three additions, starting and ending with the dry ingredients. Beat, at medium speed, after each addition only until ingredients are incorporated. Beat 30 seconds longer after all ingredients have been added.

Transfer batter to prepared pan, smoothing top with a knife or offset spatula. Place pan in oven and bake cake for approximately 45-50** minutes, or until cake tester inserted near center of cake comes out clean, cake springs back from a light touch, and cake shows signs of leaving the sides of the pan. Let cake rest in pan for apx. 10 minutes then transfer to a wire rack to cool completely.

Place butter, sugars, maple syrup, and eggnog in saucepan and, over medium heat, bring mixture to a boil then reduce heat to medium-low and boil gently for about 2 minutes, stirring occasionally. Add the rum and spices and boil on medium low for 1 minute. Remove mixture from heat and stir in vanilla. Cool glaze to room temperature. For easy clean-up, put a rimmed baking sheet or pizza pan under the cake (still on the wire rack) while applying the glaze. Let cake rest for a few minutes to allow the glaze to set then carefully transfer cake to serving plate. Or, if you wish, you can set the cake on a rimmed cake plate then apply the glaze, allowing it to puddle down around the base of the cake where it will add additional flavor and moistness to the cake base.

If garnishing cake with chopped pecans, glaze cake with part of the glaze first then add the nuts and finish with another coat of glaze.