Preheat oven to 180°C (350°F)
Line a baking tray with parchment paper
In a bowl, cream together 115 g (1/2 cup) softened butter and 100 g (1/2 cup) brown sugar
Add 1 large egg and 1 tsp vanilla extract; mix until combined
In a separate bowl, whisk together 200 g (1 1/4 cups) all-purpose flour, 1/2 tsp baking soda, and 1/2 tsp salt
Add dry ingredients to wet ingredients; mix until just combined
Stir in 150–200 g (3/4–1 cup) chocolate chips
Scoop 1–2 tbsp portions onto the tray, spacing them apart
Bake 9–12 minutes, until edges are lightly golden
Cool on the tray for 5 minutes
Transfer to a wire rack to cool completely