Use a large baking tray and line with baking paper. Preheat oven to 190°C.
Sift flour and baking powder into a large bowl. Add all the remaining ingredients and mix to a smooth dough using the dough hooks of an electric hand mixer, or by hand.
Use 2 teaspoons to scoop 12 equal mounds of the mixture onto the baking tray, placing them about 2.5 cm apart.
Bake for 12–15 minutes. Remove from oven. Leave on baking tray for 2–3 minutes to cool a little and harden slightly. Transfer cookies to a wire rack to cool completely.
To make peanut butter, place about 80 g (1/2 cup) unsalted roasted peanuts in a food processor. Blend until chunky pieces form. Remove half; process the remainder finely. Mix all the processed nuts with 1 tbsp sunflower seed oil.