Chewy Blondies

Heat oven, line tin. Heat the oven to 175°C (155°C fan) and let it run for at least 20 minutes before baking, with a shelf set in the middle. While it heats, line the 20cm metal tin with a baking-paper sling so the blondies lift out cleanly later.

Melt and cool butter. Melt the butter in a saucepan, then leave it for about 5 minutes until just warm rather than hot. Butter that's too hot will cook the egg when it's added, so a short cooling pause protects the batter's texture.

Whisk butter and sugar. Whisk the warm butter with the brown sugar for about 30 seconds until combined, then add the egg, yolk, vanilla and salt and whisk for roughly 1 minute until glossy. Mixing by hand rather than creaming keeps air out of the batter, which is why blondies turn out dense and chewy instead of cakey.

Fold in dry ingredients. Fold in the flour and baking powder with a spatula just until no dry streaks remain, then fold through the chocolate and pecans. Overmixing at this stage develops gluten and toughens the bake, so stop as soon as everything is combined.

Spread and bake. Spread the batter evenly into the lined tin and bake for 25-30 minutes. Look for a shiny, crackled, light golden top with just-set edges; a skewer pushed in 5cm from the side should come out almost clean with a little moist batter clinging to it.

Cool completely. Leave the blondies to cool completely in the tin, at least 1 hour, before lifting them out with the paper sling. The crumb is still setting as it cools, so cutting too early gives a gluey rather than fudgy slice.

Cut into squares. Cut into 16 squares once fully cool, wiping the knife between cuts for neat edges.