Preheat your oven to 375° F.
Blend the dry ingredients (cookie mix, granulated sugar) until your ingredients reach a consistent texture.
Vegan Egg Substitute: follow the instructions on your egg-replacer package. Or, if using flaxseed, measure out 2 tablespoons flaxseed and 6 tablespoons water. Grind the flax seeds into a fine powder. If you have pre-ground flaxseed, 1 1/2 tablespoons should work. Combine the flaxseed and water and then whisk until the mixture becomes gelatinous. Substitute for the eggs in the next step.
Put the wet ingredients (brown sugar, butter or margarine, eggs or egg substitute, and vanilla extract into a mixing bowl and blend until creamy.
Gradually add the dry ingredients to the wet ones while beating until fully and well-blended.
Drop rounded teaspoons of cookie dough 2 inches apart onto your ungreased cookie sheet. Cookies may be made larger by using a larger spoon such as a tablespoon but remember to leave more space between them to allow for expansion while they bake.
Make an indent in the center of each cookie with a teaspoon and then spoon jelly into the indent until full.
Put your cookies in the oven and bake for 10-12 minutes. Don't overcook.
Remove your Jelly-Filled Surprise Cookies from the oven and let them rest for a few minutes. Then, using your spatula, move the cookies from your baking sheet to a wire rack to finish cooling.