Color marzipan with green gel color, and roll it out between two sheets of food wrap. Cut out leaves and shape small thin snakes/stems. Set aside.
Strawberry Tulip Slices
Wash the strawberries and trim the leaves and the stems.Slice strawberry lengthwise to a little less than 1/8-inch thick. Cut out the tulip profile with a knife or a small cutter, and place strawberry tulip shapes onto a baking sheet lined with a silicone baking mat or parchment. Bake at 200F (90C) for about an hour; keep the oven door ajar during the baking. Remove half-dry strawberry slices from the oven and let them cool completely for about 20 minutes. While the strawberry slices are baking, prepare the cookie dough.
Cookie Dough
At medium-high speed beat room temperature butter (1 cup, 226 grams) with powdered sugar (1¼cup, 160 grams) until creamy, about 3 minutes. Gradually beat in one whole egg, Vanilla Extract (2 teaspoons), and lemon zest (1 tablespoon) (optional). Beat till combined, about 30 more seconds.
Pour flour (3 cups, 430 grams) into a bowl, whisk in salt (1/4 teaspoon).
On low speed, beat flour into the butter until cookie dough chunks are formed. If the dough appears too dry and crumbly, add one teaspoon of milk. Do not overwork the dough. Invert the chunks of dough onto a clean work surface, and knead the chunks of dough gently until the dough forms a ball, 10-15 seconds. Flatten the dough into a disk.
Roll the cookie dough between 2 sheets of parchment to about 1/8-inch thick. Chill for about 40 minutes to 60 minutes. Cut out shapes from chilled cookie dough, and transfer cutouts onto a baking sheet lined with parchment. Re-roll the scraps.
Assemble Strawberry Tulip Cookies
Use a small butter knife to help you lift the strawberry tulip slices from the silicone mat or parchment sheet. Adhere strawberry tulip slices onto the cookies, use a food-only paintbrush dipped in water to moisten the cookie, and attach marzipan leaves and the stem.
Bake Cookies
Bake the cookies at 350F/180C for 7- 8 minutes. Let cookies cool on a baking sheet for 5 minutes. Transfer to a cooling rack to cool completely