2cups(254g) all-purpose flour (may use your favorite gluten-free substitute; see notes for GF upgrade)
1teaspoonbaking powder
1teaspoonbaking soda
1teaspoonground nutmeg (freshly grated if possible)
½teaspoonkosher salt
1cup(8oz) regular sour cream (not fat-free)
For the topping:
⅔cup(133g) packed brown sugar
½cup(57g) chopped pecans
1teaspoonground cinnamon
Instructions
For the cake: Beat the butter and granulated sugar at medium speed with an electric mixer until light and fluffy. Add the eggs, one at a time, beating just until blended after each addition.
Combine the flour, baking powder, baking soda, nutmeg, and salt; add to the butter mixture alternately with the sour cream, beginning and ending with flour mixture. Beat at low speed just until blended after each addition. Spread the batter evenly into a greased 13x9-inch pan.
For the topping: Stir together the brown sugar, pecans, and cinnamon; sprinkle over the batter. Cover the baking dish with plastic wrap and chill up to 18 hours.(Optionally, you may bake right away.)
When ready to bake: Allow the coffee cake to sit on the counter while the oven preheats to 350℉. Bake for 30 minutes, give or take a few minutes depending on oven, or until the center is just cooked through. To ensure a moist, tender cake, be careful not to over bake. (Best way to bake to perfection? A quick-read thermometer should register between 200-205℉ when inserted in the center of the cake.) Serve warm or at room temperature.
Notes
Need a gluten-free coffee cake? A cup-for-cup, all-purpose substitute may be used and will work fine, but for an upgrade that rivals the glutenous recipe, I like to use 75% GF all-purpose flour and 25% finely ground almond flour. So, for this recipe, that is 1½ cups (190g) GF flour + ½ cup (56g) finely ground almond flour.Another tip: GF substitutes are often heavier than all-purpose wheat flour, providing yet another good reason to measure by weight instead of volume. I've found that using the weight of the AP wheat flour called for in a recipe ensures the best amount of GF flour is used (usually a little less than you'd measure in a cup), thus avoiding an outcome that is dense or dry.