1. Preheat & Prep: Preheat your oven to 325°F (165°C)—note that pound cake bakes better at a slightly lower temperature. Grease a 9×5-inch loaf pan generously with butter and line it with parchment paper for easy removal.

2. Cream Butter & Sugar: In a large bowl (or stand mixer fitted with the paddle attachment), beat the softened butter and granulated sugar on medium-high speed for 5-7 minutes. This step is crucial; the mixture should look pale yellow and fluffy.

3. Add Eggs: Add the eggs one at a time, beating well after each addition. Scrape down the sides of the bowl to ensure everything is incorporated. Stir in the vanilla extract.

4. Mix Dry Ingredients: In a separate medium bowl, whisk together the gluten-free flour, baking powder, and salt.

5. Combine: Reduce the mixer speed to low. Add half of the flour mixture to the butter mixture, followed by the sour cream (or yogurt). Finish by adding the remaining flour. Mix just until the batter is smooth and combined—do not overmix.

6. Bake: Pour the thick batter into the prepared loaf pan and smooth the top with a spatula. Bake for 55–65 minutes. A toothpick inserted into the center should come out clean or with just a few moist crumbs.

7. Cool: Let the cake cool in the pan for 15 minutes, then carefully lift it out using the parchment paper and transfer it to a wire rack to cool completely.

8. Glaze (Optional): Whisk together the powdered sugar, milk, and vanilla until smooth. Drizzle over the completely cooled cake before slicing.