Position a rack in the center of the oven and preheat the oven to 350°F. Oil three 9- by 5-inch loaf pans and line their bottoms with parchment paper.
In a small bowl, combine ¼ cup of the boiling water with the baking soda (to eliminate any bitterness). In the bowl of a standing mixer or with hand beaters and a large bowl, combine the sugar, honey and oil and beat at medium speed until completely combined, 2 to 3 minutes. (Alternately, mix by hand in a large bowl.) Add the eggs, 1 at a time and beating after each addition. Add the dissolved baking soda and beat until combined. Add the raisins if using, and stir to incorporate.
In a medium bowl, combine the flour, cinnamon, ginger, salt and zest and blend with a fork. With the mixer at low speed, gradually add the flour mixture to the honey mixture. When combined, slowly add the remaining 2 cups boiling water. The batter will seem quite thin and a bit runny; this is normal.
Divide the batter among the pans. Bake the cakes on the center rack until a cake tester inserted in the centers comes out clean and the tops are springy to the touch, 45 to 50 minutes. Allow the cakes to cool in their pans for 10 minutes, then transfer to a rack to cool completely. Cut the cakes in ½-inch slices and serve with the grilled peaches.