In a medium bowl, whisk together the flour, crushed graham crackers, salt and baking powder. Set aside.
In the bowl of a stand mixer (or using a hand mixer), beat together the butter and brown sugar on medium speed until light and fluffy, about 2 minutes.
Add eggs, one at a time, beating until combined after each addition. Add the vanilla and honey and mixed until incorporated.
With the mixer on low speed, slowly add the flour mixture to the bowl. Stir just until incorporated (avoid over mixing).
Transfer half the dough onto a piece of plastic wrap and shape into a disc. Wrap in plastic and repeat with remaining dough. Chill the dough in the refrigerator for at least two hours or up to overnight.
When ready to bake, preheat oven to 350 F. Line a cookie sheet with parchment paper and set side. Remove dough disc from the refrigerator and remove plastic wrap.
Generously flour a work surface and use a floured rolling pin to roll dough to 1/4-inch thickness. Use a 1 1/2-inch circle cookie cutter to cut cookies and place on prepared cookie sheet 1-inch apart. Reroll dough a repeat as necessary.
Bake cookies for 6 to 7 minutes or until the edges of the cookies turn golden brown. Cool on the baking sheet for 5 minutes then transfer to a wire rack to cool completely. Prepare key lime frosting while cookies are cooling.
Key Lime Frosting
In the bowl of a stand mixer (or using a hand mixer), beat butter and cream cheese on medium speed until fluffy, about 2 minutes. Add in lime juice and zest and mix until combined.
With the mixer on low, slowly add the powdered sugar and mix just until combined.
Transfer frosting to a piping bag fitted with a large round tip.
Assembly
Match up two graham cracker cookies that are the same size.
Pipe about 1 1/2 teaspoons of frosting on the bottom of one cookie. Place the matching cookie on top. Repeat with remaining cookies and enjoy!
Notes
Store cookies in an airtight container in the refrigerator for up to 3 days.