In a medium mixing bowl, whisk together the vegetable oil and granulated sugar until smooth.

Add the eggs and vanilla extract, and mix until fully combined.

In a separate bowl, stir together the flour, baking powder, and salt.

Gradually add the dry ingredients to the wet ingredients, stirring until a thick dough forms.

Divide the dough evenly into three bowls.

Leave one bowl plain for the white dough.

Add red food coloring gel to one bowl and blue food coloring gel to the other.

Stir each colored dough until the color is evenly distributed.

Cover all three bowls with plastic wrap and chill in the fridge for 1 hour.

Preheat your oven to 350°F.

Line two baking sheets with parchment paper.

Scoop 1-inch portions of dough and roll into balls.

For marbled cookies, press a bit of each color together before rolling.

Roll each dough ball generously in powdered sugar.

Place cookies on the baking sheets, leaving space between each one.

Bake for 10–12 minutes, or until the edges are set and the tops are crackled.

Let cookies cool on the baking sheet for 2–3 minutes.

Transfer to a wire rack to cool completely.

Store in an airtight container at room temperature for up to 5 days.