Preheat the oven to 325°F. Line a baking sheet with parchment paper.
Place the roasted peanuts in a blender or food processor and grind until a coarse crumbs form. Add the confectioners sugar and blend again until the mixture is finely ground. Scrape the bottom and sides of the bowl.
In a large bowl, combine the flour, salt and baking powder. Add the peanut-sugar mixture into the bowl and stir until combined.
Add the melted butter and oil into the bowl. Mix and knead until the whole mixture comes together into a soft dough. If the dough seems too dry, add a tablespoon more oil.
Roll the dough into 1" round balls and place them on the prepared baking sheet. Traditionally a little decorative stamp is put on top, but I used the tip of the straw to make a design.
Brush the cookies with egg replacer mixture (or egg) and then bake for 20~22 minutes until light golden in color. Transfer the cookies to a wire rack to cool completely before serving. Store in an airtight container for up to 1 week.