Coffee Walnut Cake

From Chef Oonagh Williams of Gluten-Free Cooking with Oonagh

This is the same almond flour base I made in wheat flour days. Almond flour cakes are very common in Europe and naturally gluten-free. 

Gluten-Free Cake with Coffee & Walnuts

• Cake – single 8″ cake layer about 3/4 inch deep, with coffee butter frosting. 
• 6 tbsp (3 oz, 84g) very soft butter or coconut oil. I use coconut oil as my butter substitute in baking and prefer it to margarine style subs.
• 1+1/4 cup (4oz, 112g)  almond flour – almonds ground without skin (Trader Joe’s on line state that their almond flour -white – and almond meal – freckly – are gluten free and only $4.99/lb compared to other national brands except for Costco $4/lb for 3 lb bag, labeled gluten-free)
• 1/3 c (2oz, 56 g) toasted, chopped walnuts. I toast contents of a bag of chopped walnuts in 350 oven for about 10 minutes and then store them, ready to use. Toasting nuts really does make a difference, just don’t let them burn.
• 3/4 c, (6 oz, 180 g) sugar  
• 2 Tbsp (30 ml) instant coffee powder dissolved in 1 tbsp (15ml) water – regular Folger’s
• pinch of salt
• 1+1/2 tsp (8 ml) gluten-free baking powder 
• no xanthan gum needed
• 3 eggs  
• Frosting/Buttercream:
• 1/2 cup/1 stick (4 oz, 112g) soft butter or butter substitute you like
• 1 tsp instant coffee powder dissolved in 2 tsp water. 
• 2 c (8 oz, 224g) powdered (icing, confectioners) sugar

More toasted walnuts to sprinkle on top of frosting. 

1. Preheat oven to 350*F/170*C. Lightly grease and bottom line 8”  pan with parchment paper circle, dust with rice flour. 
2. Place all the cake ingredients in a 4 cup, 1-litre bowl and beat for 1-2 minutes until smooth and creamy. Color will lighten slightly but will still be coffee-colored.
3. Spoon raw batter into prepared pan and smooth out. 
4. Bake in preheated oven for about 30 minutes until cake has risen, softly firm is dark golden brown  If you use almond meal/natural almond flour (almonds ground with skin still on) then cake will be even darker.
5. Remove from oven, cool in pan for about 3 minutes, then turn out onto cake serving plate, remove paper lining and then turn right side up.

Frosting/Buttercream:

6. I like to sieve the powdered sugar as it is often lumpy and it’s easier to sift first then try and beat little white lumps out of frosting.
7. Slowly add powdered sugar to very soft butter and coffee. Be careful, the sugar has a tendency to explode up. Once all sugar is added, beat well for 1-2 minutes to make fluffy.
8. This quantity of frosting is enough to generously top cake and pipe around edges. Then sprinkle with more toasted walnuts.

Variations:

1. Whipped Cream. Whip 1 cup of cream with 2 tablespoons powdered sugar and 2 tablespoons of Kahlua or rum until stiff.  This can be used to frost cake instead of buttercream frosting. Or just serve on the side.
2. Regular chocolate ganache with Kahlua or rum added. 

1 c (8 oz, 240 ml) heavy or whipping cream

1 c (6oz, 168g)) Nestle semi-sweet chocolate chips -labeled gluten-free.

2-4 tbsp (30-60ml)  Kahlua or rum. Depending on the alcohol content of the chosen liqueur, this can taste quite strong.

Heat 1 cup of whipping or heavy cream to nearly boiling, add chocolate chips and stir. Let stand for a few minutes, then stir and microwave more if necessary until a totally smooth sauce is formed (looks like thick chocolate syrup). You can also use an immersion blender to make the sauce totally smooth.

Add alcohol and refrigerate for several hours until stiffer than set jello pudding.

I like to lightly whisk half of chilled ganache and gently persuade over top of cake and it will start drizzling down the sides. Then whisk remaining ganache and pipe on top of cake. Ganache is very soft if served immediately, piped chocolate will set up stiffer with refrigeration.  

3. Fruit. Melt 2 tablespoons of butter with 2 tablespoons of light brown sugar, add slices of fresh or canned pineapple and gently fry until starting to brown on edges.  Pour 2 tablespoons of rum into a measuring cup, then pour into skillet, allow to heat for about 20 seconds and use gas grill lighter to ignite the alcohol fumes. Make sure there are no children or animals around.  Do not lean over pan, keep hair out of the way. Allow flames to die down and serve on side of cake. In the summer just grill some pineapple slices.