1. In a medium bowl, whisk together the bread flour, rice flour, cinnamon, nutmeg, and salt. Set aside.
2. In a small bowl, combine the warm water and yeast. Let the mixture rest for 5 minutes until foamy.
3. In a stand mixer fitted with a paddle attachment, beat the butter and sugar at medium speed until creamy, about 2 minutes. Beat in the eggs, 1 at a time. Beat in the yeast mixture. With the machine running on low speed, gradually add the flour mixture until a ball of dough forms. Remove the paddle attachment and attach a dough hook. (If a dough hook attachment isn't available, the dough can also be kneaded by hand for 15 minutes on a lightly floured work surface.) Mix on medium-low speed for 10 minutes (scraping the sides of the bowl, if necessary). Add the walnuts and raisins and continue to mix until the dough is smooth and springs back when pushed with a finger, about 5 minutes longer. Transfer the dough to an oiled bowl and cover with plastic wrap. Place in a draft-free area at room temperature (about 30°C) until the dough has puffed slightly, about 2 hours.
4. Butter and flour the inside and outer rim of an 8 1/4 by 4 1/2-inch nonstick loaf pan. Punch the center of the dough to deflate it. Place the dough on a lightly floured work surface and knead for 3 minutes. Form the dough into an 8 by 4-inch rectangle and place in the prepared loaf pan. Cover with plastic wrap and allow the dough to rise in a draft-free area at room temperature until the dough rises about 2 inches above the top of the pan, about 2 hours.
5. Place an oven rack in the center of the oven. Preheat the oven to 175°C.
6. Remove the plastic wrap and bake the loaf until golden brown, 30 to 35 minutes. Cool for 10 minutes. Remove the loaf from the pan and transfer to a wire rack to cool completely, about 1 1/2 hours.
7. Wrap well in plastic and store at room temperature for 2 days or freeze for up to 1 month.