Step 1

Preheat oven to 180 °C (350°F) conventional (see note 3 if using a convection oven with a fan) and line an 8x8 inch cake pan with parchment paper.

Step 2

Sift together flour, cornstarch, baking powder and salt. Using a whisk or fork, mix until well combined and set aside.

Step 3

Roughly chop the white chocolate (if using a block) and walnuts. Set aside.

Step 4

In a large bowl add in sugar and melted butter. Using a whisk, mix until well combined. Avoid overmixing as we don't want to incorporate too much air into the batter. If the butter is hot, let it cool slightly before moving on to the next step.

Step 5

Add in eggs and vanilla and mix until well combined - avoid overmixing. Get any batter off the whisk as the rest of the mixing will be done with a spatula.

Step 6

Add in the presifted dry ingredients into the wet mixture and using a spatula, fold until just combined. Do not overmix.

Step 7

Next add in the white chocolate and walnuts and fold until just combined. Do not overmix.

Step 8

Distribute the batter evenly into the prepared cake tin. Level the top and drop the cake tin lightly on the counter to remove any large air bubbles.

Step 9

Bake for 28-30 minutes, or until the top is lightly browned and set and a toothpick inserted into the centre comes out with a little bit of undercooked batter on the tip (see note 4).

Step 10

Allow the blondies to cool in the cake tin for about 45 minutes to set, before lifting them out using the parchment paper. Slice and serve!