1-First Step: Preheat your oven to 350°F (175°C) and prepare two 9-inch round cake pans by greasing them and lining with parchment paper. This ensures an even bake suited for high altitudes.

2-Second Step: In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. This dry mix is essential for proper rising and flavor distribution.

3-Third Step: In a large bowl, cream the unsalted butter and sugar together until fluffy, incorporating air for a lighter cake. For vegan options, use plant-based butter and a sugar that aligns with the dietary need.

4-Fourth Step: Beat in eggs one at a time, or flax eggs for vegan versions, ensuring each is fully incorporated before adding the next.

5-Fifth Step: Alternately add the dry ingredients and buttermilk to the creamed mixture, starting and ending with dry ingredients. Mix gently to avoid overworking the batter.

6-Sixth Step: Fold in the cherries and chopped pistachios evenly to distribute the flavors throughout the batter.

7-Seventh Step: Divide the batter evenly between the prepared pans and smooth the tops.

8-Eighth Step: Bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean. Baking time may vary with altitude adjustments.

9-Ninth Step: Allow cakes to cool in pans for 10 minutes, then remove and cool completely on wire racks.

10-Final Step: Once cooled, assemble your cake with frosting of choice and garnish with extra pistachios and cherries if desired. Serve and enjoy this perfectly baked high altitude cherry pistachio layer cake, ready to delight all dietary preferences.