This moist, dense and gooey Sticky Toffee Acorn Cake was made from acorns harvested from my neighbourhood. And despite the nearly full day it took to create (from harvesting, shelling, leaching, roasting and grinding – to the actual baking) it was well worth the effort! It took first prize in a most wonderful old-fashioned community harvest tea/fair organized by my sister-in-law Jennifer and my friend and neighbour Connie McConnell. (see pictures here). And I assure you there was no nepotism involved – independent community judges of course! (Well sort of!) But let’s move on…
The harvest fair was held in the park behind my home, which is situated in what was once a large Garry Oak Grove. This was once the traditional territory of the Lekwungen, and while I’m not sure if they harvested from these specific trees, according to ethnobotanist Nancy Turner, several Coast Salish tribes consumed acorns and cooked them by steaming, roasting or boiling. Some people stored them all winter in baskets buried in the damp mud, a practice that would have certainly helped to leach the bitter tannins (more on that later).
There are over 58 varieties of oak trees in North America, plus varieties of oak trees were brought by early settlers to the new world and if you have an oak tree near you – yes – you can eat the acorns! Garry Oaks are native to the Pacific Northwest and used to cover Vancouver Island (today it is estimated only 5% remain). Today many trees still stand in our neighbourhoods and so they tower over rooftops and spread a literal avalanche of glossy brown acorns over lawns and sidewalks every fall.
Sadly most of these are trod or driven over and ignored despite the fact that they are an abundant source of protein, vitamins and minerals like phosphorus, niacin, potassium, calcium and magnesium. In fact, for all nearly our ancestors, acorns were an important food source. Long before we began to cultivate wheat and grains, acorns were an abundant source of protein, fat and carbohydrates for ancient people from Europe, Russia, and the Middle East to China, to Africa. The word acorn (earlier akerne, and acharn) is related to the Gothic name akran, which roughly means “fruit of the unenclosed land”.
I think acorn flour is wonderful in baking – especially cookies, muffins and cakes.(And I’ll be including more recipes in the upcoming Gather Autumn E-Cookery Book for Gather Patrons.) Acorn flour has a mild but rich nutty flavour – once the tannins have been leached that is. Acorns contain tannins, bitter compounds that not only taste bad but can upset tummies. I’m not going to go on and list all the different ways you can leach acorns, there are many methods from hot to cold ( you can find different resources online that explore differing methods) I only want to say that this step cannot be missed – if you want your cake or baking to be edible that is.
I will give my method below, but suffice to say I chose the fastest, easiest (though not the most nutritious route to prepare my acorns) – boiling– sacrificing vital enzymes and oils in the process. If you want to know more about modern cold leaching methods, click here. After leaching, I then roasted the nuts at (another hour or so) laying them out on cookie sheets and then baking them in the oven.
And I was delighted when the house filled with a sweet, earthy, vanilla-like aroma. Who knew that acorns could smell so enticing? Once cooled I ground them in my coffee grinder and came up with 2 cups of a crumbly, mildly sweet, caramel coloured flour that is rich in flavour and high in nutrients – and of course absolutely free!
Acorns can be stored for up to a year if they are dried. So if you’re not going to use your nuts right away spread them on cookie sheets and let them sit in a warm oven at the lowest setting for a couple of hours. Acorn flour will also keep for several months if you store it in an airtight container in the refrigerator. The cold temperature prevents rancidity, extending the shelf life.
Making Acorn Flour
- Gather a small basket of acorns – about 1 & ½ lbs depending on size.
- Make sure they have no cracks or tiny holes (a weevil or worm will have bored its way in). Some foragers advise placing them in a bucket of water and discarding the acorns that float.
- Place acorns in their shells in a large pot of cold water – then boil for 5-6 minutes.
- Let cool slightly so they can be handled without burning your fingers, then begin cracking your nuts. The boiling softens the shells so that you can easily crack them between your teeth (well I did anyway). You can use a nutcracker or hammer – whatever you like to crack open the shell. With this boiling first method, the flesh will come out very easily and leave the dark papery skins behind.
- Put the shelled nuts into a large pot of water. Boil for 10 minutes. The water will turn a dark brown. Drain water. Fill the pot with water, boil and add acorns and boil again. Repeat this process until the water runs clear or until the acorns have lost their tannins (bitter taste). It took me five boils – approximately an hour of boiling. You may want to boil longer, there may still be a faint bitter taste, but this doesn’t bother me and is usually lost by the time you bake it into a dish.
- Once you’ve drained your acorn meats, lay them on a cookie sheet for roasting. Place them in a preheated 300 oven until they are dry, slightly crunchy on the outside but moist and fudgy inside – approximately 40 min.
- Once cooled grind the dried acorns in a coffee grinder to a crumbly flour consistency. If necessary use a sieve to get keep out any of the harder bits that did not grind down. Keep grinding until you have one cup of acorn flour, lightly packed. Now you are ready to make the cake!
When it comes to baking with acorn flour, it should ideally be mixed with other flours. Wheat, rice, corn, oat – whatever your choice – but remember if you choose a non-gluten flour (and mix with the non-gluten acorn flour) your cake will not rise, and be heavier. Also, keep in mind the more acorn flour you use the likelier you will end up with a denser product.
I used an all-purpose flour but also added finely chopped dates to the batter to give a soft fudgy texture to the finished cake. And to all this delectable goodness I poured a warm golden toffee sauce over the top, giving it a rich, indulgent, decidedly festive and celebratory flair. Just the gooey sweet ticket for a prize-winning acorn cake!
Sticky Toffee Acorn Bundt Cake
- 1 1/2 cups finely chopped dates (about 15 whole dates)
- 1 cup boiling water
- 1 teaspoon baking soda
- 1 teaspoon vanilla extract
- 1 cup flour
- 1 cup acorn flour
- 1 1/2 teaspoon baking powder
- 1/2 teaspoon sea salt
- 1/2 cup softened butter
- 1 cup brown sugar
- 3 eggs
Sticky Toffee Sauce
- 1 1/2 cups brown sugar, lightly packed
- 3/4 cup butter
- 1 cup heavy whipping cream
- 1/2 teaspoon sea salt
- 1 tablespoon brandy or vanilla extract (optional)
- Preheat oven to 350 degrees F. Lightly grease and dust with flour a largish bundt pan and set aside.
- In a bowl, stir together the finely chopped dates, boiling water, baking soda, and vanilla extract. Let sit for 10 minutes.
- In another bowl, whisk together the flour, baking powder, and salt. Set aside.
- Beat the butter and sugar together until light and fluffy, about 2-3 minutes. Add the eggs, one at a time, and mix until blended.
- Add the flour mixture to the wet ingredients. Fold in the date and water mixture. Do not overmix.
- Pour the batter into the prepared bundt pan. Bake for 50-55 minutes. Test with a toothpick near the centre to make sure it comes out clean. Let the cake cool for about 30 minutes before inverting it onto a cooling rack covered with parchment paper.
- For the sauce, bring the brown sugar, butter, and cream to a boil in a small saucepan over medium heat, stirring constantly for 5 minutes. Remove from the heat and stir in brandy (One teaspoon vanilla can be used in place of the brandy.)
- Poke a few holes in the top of your cake with a skewer then pour the first layer of warm sauce over the cake. Let soak in, then dribble over another layer. Repeat until you’ve got just a bit of sauce left for serving.
- Then sprinkle a little bit of rose sugar on your cake and garnish with something pretty. If you don’ have rose sugar – well brown sugar will do! Then slice the cake and serve it with ice cream and a little splash of additional toffee sauce!