Step 1

Preheat the oven to 350 degrees. Grease a 9-inch roundspringform pan with baking spray.

Step 2

In a medium bowl, whisk together the flour, baking powder,nutmeg, cinnamon, baking soda, and salt.

Step 3

In the bowl of a mixer, cream the butter and sugar with anelectric mixer on medium speed until light and fluffy, about 3 minutes. Add in the egg and egg yolk, one at a time and beating to incorporate after each addition. Beat in the vanilla until combined.

Step 4

Reduce speed to low and add in the dry ingredients in threebatches, alternating with the sour cream and mixing until just combined after each addition. Add in the eggnog and mix until combined. After the final addition, increase mixer speed to medium and beat until well combined, about 30 seconds.

Step 5

Spoon batter into prepared pan and evenly smooth the top. Setaside while you make the topping.

Step 6

In a separate bowl, combine the flour, sugar, cinnamon,nutmeg, and salt. Using your fingers, work in the cold butter into the flour mixture until clumpy.

Step 7

Scatter the topping over the batter.

Step 8

Bake until golden brown and toothpick inserted in centercomes out clean, about 70 minutes.

Step 9

Transfer to a cooling rack and let cake cool in the pan for20 minutes before removing and letting cool completely.

Step 10

Make the glaze: in a medium bowl, whisk the confectioner’ssugar with 3 tablespoons eggnog until smooth. Add more eggnog to desiredconsistency.

Step 11

Drizzle the glaze over the cake before serving.