Petit Four Butter Cookies (Vanilla and Chocolate)

Vanilla Petit Four Butter Cookies
0 Preheat oven to 350°F (180°C).
6 In a large mixing bowl, add butter, powdered sugar, and whole eggs. Mix until smooth and creamy.
5 Add sifted flour, vanilla extract, and salt. Mix just until a soft dough forms.
3 Transfer dough into a cookie press or piping bag fitted with a large star tip.  I use this cookie press to make these petit four cookies.If using a cookie press, use a flat, clean, nonstick baking sheet with no parchment paper so the dough sticks properly.If using a piping bag (recommended tip: Wilton 6B), use a flat nonstick baking sheet.
4 Pipe or press shapes directly onto the prepared baking sheet.
2 Bake for 10–12 minutes, or until edges are lightly golden and cookies are set but pale on top.
1 Cool the vanilla petit four cookies on a pan for 5 minutes, then transfer them to a wire rack to cool completely.
Chocolate Petit Four Butter Cookies
8 Preheat oven to 350°F (180°C).
13 In a large mixing bowl, beat butter, powdered sugar, and whole eggs until smooth and creamy.
14 Add sifted flour, sifted cocoa powder, vanilla extract, and salt. Mix until a soft chocolate dough forms.
9 Transfer the dough into a piping bag or cookie press.Use a flat, clean, nonstick baking sheet. If piping, use a Wilton 6B star tip for classic shape.
12 Pipe or press shapes onto the baking sheet.
11 Bake for 10–12 minutes, or until cookies are set and firm but not dry or browned.
10 Cool the chocolate petit four cookies on a pan for 5 minutes, then transfer them to a wire rack.
Half Vanilla + Half Chocolate (One Batch Method)
17 Prepare the full vanilla dough using the vanilla ingredient list and instructions.
23 Divide the dough evenly into two equal portions.
22 Leave one half plain vanilla.
18 To the second half, add ¼ cup sifted unsweetened cocoa powder.
21 Mix gently until cocoa is fully incorporated and dough is evenly chocolate-colored.
20 Pipe or press both doughs separately.
19 Bake the vanilla cookies for 10–12 minutes and the chocolate cookies for 10–12 minutes.
Chocolate Ganache Filling
24 Heat the heavy cream in a small saucepan until steaming, but do not let it boil.
26 Pour the hot cream over the chocolate in a heat-safe bowl.
30 Let the mixture sit undisturbed for 2 minutes to allow the chocolate to melt.
29 Add the butter, if using, and whisk until smooth and glossy.
28 Allow the ganache to cool for 10–15 minutes until thick and spreadable.
27 Use immediately to sandwich cookies or pipe between layers.