Preheat the oven to 175°C (350°F) and line two large baking sheets with parchment paper.

In a medium bowl, sift together the all-purpose flour, cinnamon, baking soda, and salt.

In a stand mixer fitted with the paddle attachment, cream 115g of butter with the granulated sugar and 60ml of honey until the mixture is light and aerated.

Add the egg and beat until fully incorporated, scraping down the sides of the bowl as needed.

Gradually add the dry ingredients to the wet mixture on low speed, then fold in the finely chopped walnuts until just combined.

Scoop 24 equal portions of dough (approximately 1 tablespoon each) and place them 2 inches apart on the prepared sheets.

Bake for 10 to 12 minutes until the edges are set and lightly golden; transfer to a wire rack to cool completely.

To prepare the cream filling, beat the remaining 115g of butter until smooth and creamy.

Gradually add the powdered sugar, 2 tablespoons of honey, vanilla bean paste, and 0.5 teaspoons of cinnamon, whipping on high speed until the texture is light and fluffy.

Pipe or spread the honey buttercream onto the flat side of 12 cookies.

Place the remaining 12 cookies on top of the frosting, pressing gently to form sandwiches.

Roll the edges of the sandwich cookies in the crushed pistachios so the nuts adhere to the exposed cream filling.