Please choose the correct ending to complete the given sentence: Food and Entertaining: [header] How to make gluten free chocolate chip cookie bars [title] Preheat the oven to 350 ° f/180ºc. [title] Lightly grease a 9 " x 13 " baking pan. [title] In a large bowl, whisk together the baking flour, xanthan gum, salt, baking powder and the baking soda. [title] Add the flax meal, and whisk until combined.

Ending1: [title] Roll the dough out on a floured surface. [step] Roll out 2 " x 3 " (7.6 cm x 10.8 cm) sticks. Ending2: [title] In a second large bowl, beat the egg yolks together, and the substitute shortening. [title] Beat together the dry ingredients with the whisk. Ending3: [title] Drop cookie dough onto the greased 9 " x 13 " surface. [title] Press the cookies into the heated hot pan. Ending4: [step] The flaxseed works in place of an egg; it helps to bind and it adds fiber. [title] Stir in the brown sugar and whisk until combined.

Answer format: ending1/ending2/ending3/ending4