Step 1

Heat the oven to 350ºF (175ºC). Coat a 6-cup (see notes above) loaf pan well with nonstick spray or butter, and line with a sling of parchment paper that extends up the two long sides.

Step 2

In a large bowl, whisk together the melted butter, 1 cup granulated sugar, all of the turbinado sugar, and the salt. Add the eggs one at a time, whisking after each addition. Add the sour cream, vanilla extract, and vanilla bean paste, if using, and whisk until smooth. Sprinkle the baking powder over the surface of the batter, and whisk many more times than are needed to make it disappear (to ensure it is very well dispersed through the batter). Add the flour, and stir with a spatula until just combined.

Step 3

Scrape the batter into the loaf pan, and drop the pan on the counter a couple of times to release any trapped air. Smooth the top, and sprinkle with the remaining 1 tablespoon granulated sugar (see notes above).

Step 4

Bake for 1 hour and 10 to 15 minutes, until a skewer inserted all over comes out batter free. If you are baking in mini loaf pans, start checking after 30 minutes. Depending on the size of your pan, it will take more or less time after that. My three minis were done in about 42 minutes total. Let it cool in the pan. Run a knife along the short sides of the cake, and use the parchment sling to remove the cake for slicing.

Step 5

Store the cake at room temperature for 5 days. Deb stores it in its loaf pan with the top uncovered so that it stays crisp. She presses a piece of foil against the cut side of the loaf only.