Preheat the oven to 325 degrees F (165 degrees C).

Combine almond flour, coconut flour, butter, and 1 tablespoon honey in a bowl. Use fingers to press the crust mixture into a tart pan.

Bake in the preheated oven for 12 minutes. Remove crust from oven and increase temperature to 350 degrees F (175 degrees C).

Slice unpeeled blood orange into thin slices. Combine blood orange slices, honey, and water in a small saucepan. Bring to a simmer over medium-high heat and simmer until juices thicken, 10 to 20 minutes. Use tongs to remove blood orange slices and set on a baking sheet lined with wax paper to cool.

Meanwhile, combine eggs, sweetened condensed milk, butter, honey, vanilla extract, blood orange juice, and blood orange zest in a bowl; beat using an electric mixer until well combined. Pour filling into the warm crust.

Bake in the preheated oven for 15 minutes. Remove from oven, leaving oven on. Carefully top with candied blood orange slices, slightly overlapping each slice. Return tart to oven.

Bake until filling is just set, 15 to 20 more minutes. Remove from oven and allow to cool slightly before serving.