Gluten-free rhubarb and caramel upside down cake

This recipe comes from Coeliac New Zealand ambassador Sally Holland, from her cookbook Goodbye Gluten.

Ingredients

¼ cup	Water
½ cup	Caster sugar
4 stems	Rhubarb, trimmed and cut in to 3cm lengths
185 g	Butter, softened
1 cup	Sugar
1 ½ tsp	Vanilla extract
4 large	Eggs
1 ½ cups	Gluten-free flour mix, see below
1 ½ tsp	Baking powder, gluten-free
¾ cup	Sour cream

Directions

1. Heat oven to 165C. Prepare a 23cm round cake tin by heavily buttering the base.
2. Place water and sugar in a small saucepan. Slowly bring to the boil, stirring to dissolve the sugar. Allow to boil over medium heat until the syrup turns golden, about 5 minutes. Do not stir at this stage.
3. Pour into the tin and swirl the tin to spread the toffee evenly over the base. Arrange the sliced rhubarb on top of the toffee. Set aside while preparing the cake batter.
4. Cream butter and sugar until light and fluffy. Add vanilla, then eggs, one at a time, beating well after each addition. Gently fold in the sifted flour mix and baking powder. Fold in the sour cream.
5. Turn out on to the rhubarb and spread evenly. Bake 60–70 minutes, or until a skewer comes out clean. Immediately after removing the cake from the oven, run a knife around the edge of the tin to prevent any toffee sticking to it.
6. After a few minutes turn the cake out on to a wire rack to cool.

Gluten-free flour mix

Sally has used white rice flour and cornflour from maize, not wheat. Xanthan gum is made from corn sugar and is used as a gluten substitute to give elasticity in gluten-free baking. Tapioca flour is also known as arrowroot.

Sift 2 cups rice flour, 1 cup tapioca flour, 1 cup cornflour, 2 Tbsp xanthan gum into a large mixing bowl. Using a wire whisk, slowly stir until well-blended. Transfer to an airtight container. Makes 4 cups.

Another of Sally's gluten-free baking recipes

• Gluten-free Date and orange scones