Here is the recipe from HHB
(makes about 25~28 cookies, slightly less than 2" each)
90g butter, softened at room temperature
25g caster sugar
25g brown sugar
1 egg (weights about 60g with shell), lightly beaten
1 teaspoon pure vanilla extract
1/4 teaspoon salt
100g cake flour (or plain flour)
100g rolled oats
50g walnuts, coarsely chopped
60g dried cranberries, cut into smaller chunks
1. Preheat oven to 190 degrees. Line baking trays with parchment paper.
2. With manual whisk, cream butter and sugar in a mixing bowl until the mixture turns pale and fluffy (alternatively use an electric mixer if desired).
3. Dribble in the egg gradually. Mix well after each addition. Add in salt and vanilla extract, mix to incorporate into the batter.
4. Sift the flour over the batter, fold in with a spatula.
5. Add rolled oats, walnuts and dried cranberries. Mix well with the spatula.
6. Drop tablespoonfuls of the cookie dough onto the prepared baking tray. Leave some space between the cookies to allow for spreading (actually, they don't spread too much). Flatten each cookie dough slightly with the back of a fork, keeping the shape as even as possible.
7. Bake for 8~10 mins or until golden (my oven took 12~15mins). If necessary, rotate the baking tray halfway through the cooking time to ensure even browning. Transfer to a wire rack to cool completely. Store in air-tight containers.