Preheat oven to 350°F (175°C). Line a baking sheet with parchment paper.
In a mixing bowl, whisk together all-purpose flour, almond flour, sugar, baking powder, and salt.
Stir in sliced almonds and orange zest.
In another bowl, combine orange juice, vegetable oil, and vanilla extract.
Add wet ingredients to dry ingredients and mix until combined.
Shape the dough into a log and place it on the prepared baking sheet.
Bake for 25 minutes, then remove from oven and let cool for 10 minutes.
Slice the log into ½-inch thick slices and place them back on the baking sheet.
Bake for another 15 minutes until golden brown.
Let cool completely before serving.