- '1/2 cup (1 stick) unsalted butter plus more for pan'
- '2 large eggs
- lightly beaten'
- '1/2 cup buttermilk'
- '1 large zucchini (about 10 ounces)'
- '1 cup all-purpose flour'
- '1/2 cup whole wheat flour'
- '1/2 cup sugar'
- '1 teaspoon baking powder'
- '3/4 teaspoon fine sea salt'
- '1/2 teaspoon baking soda'
- '3/4 cup medium-grind cornmeal'
- Position a rack in the middle of oven and preheat to 350°F
- Butter a 9x5x3" loaf pan
- Melt 1/2 cup butter in a small saucepan over medium-high heat
- Continue cooking until butter solids at bottom of pan turn golden brown, about 3 minutes
- Scrape butter into a medium bowl
- Set aside and let cool
- Whisk in eggs and buttermilk
- Trim zucchini ends
- Thinly slice five 1/8" rounds from 1 end of zucchini and reserve for garnish
- Coarsely grate remaining zucchini
- Add to bowl with butter mixture and stir until well blended
- Sift both flours, sugar, baking powder, salt, and baking soda into a large bowl
- Whisk in cornmeal
- Add zucchini mixture; fold just to blend (mixture will be very thick)
- Transfer batter to prepared pan and smooth top
- Place reserved zucchini slices atop batter down center in a single layer
- Bake bread until golden and a tester inserted into center comes out clean, 55-65 minutes
- Let cool in pan 10 minutes
- Remove from pan; let cool completely on a wire rack
- DO AHEAD: Can be made 1 day ahead
- Store airtight at room temperature