For this recipe, I used Bob’s Red Mill dark rye flour. You can also buy light rye flour, in which some parts of the grain have been removed before milling, but Boyce suggests the dark type, which has a deeper, nuttier flavor, and I second her recommendation.
As for jam, choose any one you like, but make sure that it has a good level of brightness and acidity. That’ll help it hold up to the richness of the buttery crust. Also, if you come up a little short, don’t worry. I only had 1 ¼ cups, not 1 ½ cups, and it was no problem.
Set a rack in the middle of the oven, and preheat to 275°F. Rub a 9-inch springform pan with butter, or grease with cooking spray.
To make the shortbread crust, combine the flours, sugar, and salt in a large bowl, and whisk to mix well. Add the melted butter and vanilla extract, and stir until thoroughly combined. (I found the mixture a little dry at first, so I put my hand in and squeezed and massaged a bit to bring the dough together.) Using your hands, press the dough evenly into the bottom of the prepared pan. Put the pan in the freezer for 30 minutes, while you make the crumble. [Or, if you’re doing this step ahead of time, wrap the pan in plastic wrap and put it in the fridge or freezer. If it’s in the fridge, just remember to transfer it to the freezer for 30 minutes before baking.]
To make the crumble, put all of the crumble ingredients except the melted butter into the bowl of a food processor, and pulse until the oats are partially ground, about 5 or 10 seconds. Pour the mixture into a bowl. Add the melted butter and stir with your hands, squeezing the mixture as you stir to create small crumbly bits. Set aside. [Or, if you’re doing this step ahead of time, wrap the bowl in plastic wrap and put it in the fridge. Take it out about 30 minutes before using, and if needed, use a fork to break up any giant clumps that have hardened.]
Bake the frozen shortbread until pale brown and firm when touched, about 50 to 55 minutes. Remove from the oven, and raise the oven temperature to 350°F.
To assemble the bars, spread the jam over the shortbread crust, and then top with the crumble, evenly sprinkling it over the surface and squeezing bits of it together to create irregular nubs. Bake for 50 to 55 minutes, or until golden brown on top, rotating the pan halfway through for even baking.
When the pan is cool enough to handle but still warm, run a sharp knife around the edge of the pan to loosen any jam that may have stuck. Remove the ring. Completely (or mostly, anyway) cool the bars on the pan base before cutting into wedges.
Note: These bars are best when eaten in fairly short order. After three days or so, the flavors taste less clear.
Yield: Boyce says 10 wedges, but these bars are rich, so I’d say more than that. Maybe 12 to 16 wedges, depending on the size you choose
This batter requires an overnight rest, so keep that in mind when you decide to make it! Most of the work is done the night before, and that requires some planning, but you’ll be amply rewarded in the morning.
This recipe uses active dry yeast, which should not be confused with instant (also sold as “rapid rise”) yeast. And as for the warm water and warm milk, they need not be very warm. Tepid is fine. In any case, it’s better to err on the cool side than the hot side. The most recent time I made this recipe, I actually didn’t warm the milk at all, and it was absolutely okay. The only thing to watch out for with cold milk, though, is that it could re-solidify the melted butter. So if you happen not to warm your milk, for whatever reason, just do as I did: briefly mix together the milk, salt, sugar, and flours, and then stir in the melted butter bit by bit. This way, the cold milk and melted butter don’t run straight into each other and make trouble.
I use one-third buckwheat flour here, and that seems just about right. A word of caution: I wouldn’t use too much buckwheat flour in this recipe, because buckwheat flour is gluten-free, and you need a certain amount of gluten for structure. I’m sure there are other recipes, though, for making gluten-free buckwheat waffles, should you wish to.
Most waffle recipes work in any kind of waffle maker, but I think this one was made ideally for use on a standard (not Belgian) waffle maker. Mine is Belgian-style, and the batter is a bit too thin to really fill it properly. It’s not a biggie, though. The finished waffles just look prettier on one side than the other.
Pour the water into a large mixing bowl. (The batter will rise to double its volume, so keep that in mind when you choose the bowl.) Sprinkle the yeast over the water, and let stand to dissolve, about 5 minutes. Then add the milk, butter, salt, sugar, and flours, and stir well, until smooth. Cover the bowl with plastic wrap, and let it stand overnight at room temperature.
When you’re ready to cook the waffles, preheat a waffle maker. Follow your waffle maker’s instruction manual for this, but you’ll probably want to heat it on whichever setting is approximately medium-high. My waffle maker has a heat dial that runs from 1 to 7, and I turn it to 5. My waffle maker is nonstick, so I don’t grease it, and Marion Cunningham doesn’t call for greasing it, either.
Just before cooking the waffles, add the eggs and baking soda to the yeasted batter, and stir to mix well. The batter will be very thin. Pour an appropriate amount of batter into your hot waffle maker: this amount will vary from machine to machine, and you should plan to use your first waffle as a test specimen, which you get the treat of eating while you cook the rest. Cook until golden and crisp.
Yield: I wind up with 12 Belgian waffles, but yield depends on the size and configuration of your waffle iron