Preheat the oven to 350°F and grease the bundt pan thoroughly, coating every curve so the cake releases cleanly.
Whisk the flour, baking powder, baking soda, and salt in a bowl until evenly blended with no visible clumps.
Beat the butter with granulated and brown sugar for 3 to 4 minutes until pale and fluffy. Keep mixing until the texture lightens.
Add the eggs one at a time, mixing well after each. Stir in Greek yogurt, milk, vanilla extract, and almond extract until smooth.
Gradually mix in the dry ingredients just until combined. Stop as soon as the batter comes together to keep the cake tender.
Fold in the walnuts, pistachios, and cinnamon. The batter should be thick but easy to spread, with nuts evenly distributed.
Pour the batter into the prepared pan and smooth the top. Bake for 45 to 50 minutes, until a toothpick comes out clean and the top springs back lightly.
While the cake bakes, combine honey, water, lemon juice, and orange zest in a saucepan. Bring to a boil, then simmer for 5 minutes until slightly thickened.
Let the cake cool in the pan for 10 minutes, then invert onto a serving plate. Drizzle the warm syrup slowly over the cake so it soaks in.
Garnish with extra chopped nuts if desired and serve warm or at room temperature.