Preheat the oven to 350° F (180° C).
In the bowl of a stand mixer or with an electric hand mixer, cream together the butter and brown sugar until light in color and fluffy in texture.
Mix in the eggs and vanilla extract until well combined.
Add the whole wheat flour and baking powder to the bowl and mix until a firm dough forms.
Roll the dough out onto a floured surface until about 1/4 of inch thick.
Use cookie cutters to cut your animal cookies into your desired shape.
Place the cut out cookies onto a parchment or silicone lined cookie sheet.
Bake in a 350° (180° C) oven for 9-11 minutes or until the edges begin to turn golden brown.
Allow the cookies to cool completely on the pan.
Store in an airtight container for up to 5 days at room temperature or in the freeze for up to 3 months.